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Journal 


OF    THE 


Royal 
Microscopical  Society; 

CONTAINING   ITS  TRANSACTIONS   AND   PROCEEDINGS, 

AND   A   RECORD   OF   CURRENT    RESEARCHES   RELATING   TO 

INVERTEBRATA,     CRYPTOGAMIA, 
MICROSCOPY,   &c. 


Edited,  under  the  direction  of  the  Publication  Committee,  by 

PRANK    CRISP,     LL.B.,    B.A.,     P.L.S., 

ONE   OF   THE   SECRETARIES    OF   THE   SOCIETY, 

VOL.  II.     PART  1. 


PUBLISHED   FOR  THE   SOCIETY   BY 

WILLIAMS    &   NORGATE, 

LONDON    AND    EDINBURGH. 
1879. 


UBRARY 
NEW  YORK 

PREFACE.         BOTANICAL 
GARDEN 


The  substantial  increase  during  the  present  year  in  the  finances 
of  the  Society,  has  rendered  it  possible  to  increase  the  quantity 
of  matter  in  the  Journal,  and  it  is  hoped  it  will  be  found  to  be 
improved  in  quality  also. 

In  addition  to  the  "  Transactions  "  and  "  Proceedings  "  of  the 
Society,  the  "  Bibliography  "  and  "  Eecord  "  now  form  a  large 
part  of  each  number.  The  former  provides  a  classified  Index,  in 
English,  to  the  contents  of  upwards  of  three  hundred  British  and 
Foreign  Scientific  Journals  and  Transactions,*  whilst  the  latter 
consists  of  abstracts  of  or  extracts  from  the  more  important  of  the 
articles  noted  in  the  Bibliography. 

The  object  of  this  part  of  the  Journal  is  to  meet  a  wish 
which  has  been  for  many  years  expressed  by  the  Fellows — not  only 
those  resident  in  the  country,  to  whom  the  Library  is  less  accessible, 
but  those  in  London  also — that  steps  should  be  taken  for  obviating 
to  some  extent  the  difficulty  that  has  hitherto  existed  (owing  to  the 
great  development  in  modern  times  of  Periodical  Scientific  Litera- 
ture) in  ascertaining  what  is  being  done  by  Biologists  of  this  and 
other  countries. 

Whilst   the  Annual   Piecords  published  in  this  country  and 

abroad  (all  of  which  are  to  be  found  in  the  Library)  are  invaluable 

as  books  of  reference  beyond  anything  to  which  a  Journal  issued 

bi-monthly  could  attain,  the  feeling  has  been  that  a  more  readable 

account  of  the  results  of  research  would  be  useful,  and,  if  possible, 

one  not  so  much  out  of  date.     As  an  instance,  Mr.  Geddes'  very 

c<t     interestsng  researches  on  Chlorophyll  in  the  Green  Planariae  may 

^      be  referred  to.     In  ordinary  course  a  more  or  less  brief  reference 

T-^      to  this  observation  would  appear  in  the  Annual  Summaries  of  the 

O      second  (in  a  few  cases  the  first)  year  after  its  announcement.     It 

0}      is  obviously  very  desirable  that  the  Fellows  should,  in  such  a  case, 

^  *  In  a  memorial  recently  presented  to  Professor  E.  Coues,  of  the  United 

H-^  States,  signed  by  Professors  Flower  and  Huxley,  Mr.  Darwin,  and  others,  the 
memorialists  say: — "The  want  of  indexes  to  the  ever-increasing  mass  of  Zoo- 
logical literature  has  long  been  felt  by  all  workers  in  eveiy  department  of 
science,  but  the  enormous  labour  of  compilation  has  hitherto  deterred  many  from 
undertaking  a  task  so  appalling." 


iv  PREFACE. 

be  in  possession  of  fuller  and  earlier  information  of  the  author's 
views.* 

As  the  Society's  domain  includes  the  Invertebrata  and  the 
Cryptogamia  generally,  with  the  Embryology  and  Histology  of  the 
higher  Animals  and  Plants,  and  Microscopy  (properly  so  called), 
the  Bibliography  and  Eecord  extend  to  those  subjects  also. 

The  difficulty  that  has  hitherto  prevented  a  nearer  approach  to 
completeness  in  the  Bibliography— that  of  perfecting  arrangements 
at  short  notice  for  obtaining  ready  access  to  all  the  Journals  and 
Transactions  which  it  is  intended  ultimately  to  include — is  now,  it 
is  hoped,  in  a  fair  way  to  be  overcome. 

With  regard  to  the  Eecord,  the  matter  stands  on  a  different 
footing,  the  greater  or  less  completeness  in  this  case  necessarily 
depending  upon  the  Society's  finances.  Whilst  the  fullest  use  has 
been  made  of  the  means  at  command,  the  result  falls  short  of  what 
it  is  hoped  will  ultimately  be  accomplished.  It  requires,  however, 
a  larger  expenditure  than  the  Society  can  at  present  prudently 
devote  to  that  purpose. 

It  will  have  been  obvious  that  the  production  of  the  later 
numbers  of  the  Journal  was  beyond  the  powers  of  any  one  person 
(at  least  when  the  only  time  that  could  be  devoted  to  it  was  by- 
way of  relaxation  from  engagements  having  a  primary  claim) ; 
and  the  Society  have  been  fortunate  in  obtaining  the  assistance 
of  Mr.  T.  Jeffery  Parker,  Mr.  A.  W.  Bennett,  and  Professor  F. 
Jeffrey  Bell,  to  whose  abihty  and  energy  the  success  of  what  has 
been  accomplished  is  very  largely  due.  As  their  share  in  the  pro- 
duction of  the  Journal  is  now  so  important,  their  names  will  in 
future  be  associated  with  it. 

An  acknowledgment  is  also  due  to  the  Publication  Committee 
fconsisting  of  Dr.  Braithwaite,  Dr.  Millar,  Mr.  Stephenson,  and 
Mr.  Stewart)  for  much  care  bestowed  on  the  revision  of  the  Eecord, 
and  for  many  suggestions  which  have  contributed  to  the  improve- 
ment of  the  Journal. 

Frank  Crisp. 

*  Whilst  we  fully  recognize  the  conQpliment  that  is  involved  in  the  transfer 
of  the  foreign  abstracts  of  the  Record  to  other  pages,  and  the  exceptional 
appreciation  evinced  by  referring  to  the  original  foreign  source  only  (the  editor 
evidently  intending  thereby  to  show  that  he  is  prepared  to  take  the  responsibility 
of  having  the  abstracts  attributed  to  himself),  it  would,  on  the  whole,  we  suggest, 
be  better  to  adhere  to  the  rule  which  we  uniformly  observe,  of  giving  both  sources 
in  the  reference  note. 


CONTENTS. 


Transactions  op  thk  Society —  page 

I. — On  (Ecistes  umhella  and  other  Rotifers.    By  0.  T.  Hudson. 

M.A.,  LL.D.,  V.P.R.M.S.     (Plates  I.  and  II.)   .,      ..    No.  1         1 

II. — A  Further  Inquiry  into  the  Limits  of  Microscopic  Vision 
and  the  delusive  application  of  Fraunhofer's  Optical 
Law  of  Vision.     No.  II.     By  Dr.  Eoyston-Pigott,  M.A., 

F.E.S.,&c.    (Plate  III.) „  9 

III. — On  some  Recent  Forms  of  Camera  Lucida.    By  Frank 

Crisp,  LL.B.,  B.A.,  Sec.  E.M.S.,  &c.    (5  figs.)    ....       „  21 

rV. — Description  of  a  New  Form  of  Camera  Lucida.     By  J. 

Cunningham  Russell,  M.D.,  Lancaster.    (2  figs.)        . .       „  25 

v.— Immersion  Illuminators.    By  J.  Mayall,  jim.,  F.R.M.S.      „  27 

VI. — Note  on  a  Revolver  Immersion  Prism  for  Sub-stage  Illu- 
mination.  By  James  Edmunds,  M.D.,  M.R.C.P.  Lend., 

F.R.M.S.,  &c „  32 

VII. — A  Catoptric  Immersion   Illuminator.      By  John  Ware 

Stephenson,  F.R.A.S.,  Treas.  R.M.S.    (1  fig.)    ....       „  36 

.  VIII.— The  Thallus  of  the  Diatomacese.     By  F.  Kitten,  Hon. 

F.R.M.S „  38 

IX.— The  President's  Address.     By  H.  J.  Slack,  F.G.S.        ..    No.  2     113 
X. — Observations  on  Dactylocalyx  ptuniceus  (Stutchbury),  with 
a  Description  of  a  New  Variety,  Dactylocalyx  Stutchbury  i. 
By  W.  J.  Sollas,  M.A.,  F.G.S.,  &c.     (Plates  V.-VIII. 

and  4  figs.)         „        122 

XL— The  Aperture  Question.     By  J.  Mayall,  jun.,  F.R.M.S.      „        134 
XII. — A  Contribution  to  the  Knowledge  of  British  Oribatidae. 
By  A.  D.  Michael,  F.R.M.S.,  with  the  assistance  of 
C.  F.  George,  M.R.C.S.E.  (of  Kirton  Lindsay).   (Plates 

IX.-XI.) No.3    22.5 

XIII. — Notes  on  the  Pygidia  and  Cerci  of  Insects.     By  Henry 

Davis,  F.R.M.S „        2.52 

XIV. — On  Stephenson's  System  of  Homogeneous  Immersion 
for  Microscope  Objectives.    By  Professor  E.  Abbe,  of 

Jena,  Hon.  F.R.M.S „        256 

XV. — The  Vertical  Illuminator  and  Homogeneous  Immersion 
Objectives.     By  J.  "W.  Stephenson,  F.R.A.S.,  Treas. 

R.M.S. „        266 

XVI. — Note  on  Diagrams  (Plate  XII.)  exhibiting  the  Path  of  a 
Ray  through  Tolles'  a  Immersion  Objective.  By  Pro- 
fessor R.  Kdth  „        269 

VOL.  II.  6 


VI  CONTENTS. 

PAGE 

XVII.— Note  on  Mr.  Wcnham's  Paper  "  On  the  Measurement  of 
the  Angle  of  Aperture  of  Objectives."  By  Professor 
K.Keith No.  3    270 

XVIII.— Keply   to    the    foregoing  Note.      By  F.   H.   Weuliam, 

F.R.M.S „        271 

XIX. — On  the  Development  and  Eetrogression  of  the  Fat-cell. 
By  George  Hoggan,  M.B.,  and  Frances  Elizabeth 
Hoggan,  M.D.    (Plates  XIII.  and  XIV.  and  1  tig.)  ..    No.  4     353 

XX. — On  some  Applications  of  Osmic   Acid   to  Microscopic 

Purposes.    By  T.  Jeffery  Parker,  B.Sc,  F.R.M.S.     ..       „        381 

XXI. — Is  not  the  Rotiferous  Genus  Pedalion  of  Hudson  syno- 
nymous with  Hexarthra  of  Ludwig  Schmarda?  By 
JulienDeby,  F.R.M.S „        384 

XXIL— Note'on  M.  Deby's  Paper.     By  0.  T.  Hudson,  LL.D., 

V.P.R.M.S.    (2  figs.)       „        386 

XXIII. — An  Illuminating  Traverse-Lens.    By  Robert  B.  Tolles,  of 

Boston,  Mass.,  U.S.     (1  fig.) „        388 

XXIV. — On  the  Occurrence  of  Recent  Heteropora.     By  Arthur 

Wra.  Waters,  F.G.S.    (Plate  XV.)       „        390 

XXV. — Note  on  Homogeneous  Immersion  Object-glasses.     By 

F.  H.  Wenham,  F.R.M.S „        394 

XXVI. — On  a  New  Species  of  Excavating  Sponge  (Alectona  Mil- 
Ian)  •  and  on  a  New  Species  of  Hhaphidotheca  (i?. 
affinis).    By  H.  J.  Carter,  F.R.S.,  &c.    (Plates  XVII. 

andXVIIa.,  Figs.  1-4) No.  5     493 

XXVII. — On  a  New  Genus  of  Foraminifera  (Aphrosina  informis); 

and  Spieulation  of  an  unknown  Sponge.      By  H.   J. 

Carter,  F.R.S.,  &c.     (Plate  XVIIa.,  Figs.  5-12)        ..       „        500 

XXVIII. — On  the  Theory  of  Illuminating  Apparatus  employed  with 

the  Microscope.    Part  I.    By  Dr.  H.  E.  Fripp,  Ex.-Off. 

F.R.M.S.    (9  figs.) „        503 

XXIX. — Observations  on  Notommata  Wcrneckii,  and  its  Para- 
sitism in  the  Tubes  of  Vaucheria.     By  Professor  Bal- 

biani.     (Plate  XVIII.) „        530 

XXX. — On   a   New  Species    of  Cothumia.      By   John  Davis, 

F.R.M.S.     (Plate  XX.) No.  6     653 

XXXI. — On  some  Causes  of  Brownian  Movements.    By  William 

M.  Ord,  M.D.  Lond.,  F.R.M.S.,  &c.    (2  figs.)     ....       „        656 
XXXII. — Observations   suggested   by   the   Study  of  Amphipleura 
pellucida,  mounted  in  Canada  Balsam,  by  Lamplight 
and   Sunlight,   with  various    Objectives.      By   J.    J. 
Woodward,  Surgeon  and  Brevet    Lieutenant- Colonel 

U.S.  Army,  Hon.  F.R.M.S ,        663 

XXXIII. — Note  on  Abbe's  Experiment  on  Pleurosigma  angulaium. 
By  J.  J.  Woodward,  Surgeon  and  Brevet  Lieutenant- 
Colonel  U.S.  Army,  Hon.  F.R.M.S. ,        675 


CONTENTS.  Til 

PAGE 

XXXIV. — New  Species  and  Varieties  of  Diatomaceae  from  the 
Caspian  Sea.  By  A.  Grunow,  Hon.  F.R.M.S.  Translated 
with  additional  Notes  by    F.  Kitton,   Hon.  F.R.M.S. 

(Plate  XXI.)         No.  6    677 

XXXV.— On  the  Morphology  of  Vegetable  Tissues.     By  W.  H. 

Gilburt,  F.R.M.S.     (Plates  XXII.  and  XXIII.)   ..      ..    No.  7     801 

XXXVI. — Note  on  the  Structure  of  the  Scale  of  a  Species  of  the 

Genus  Mormo.     By  Joseph  Beck,  F.R.M.S „        810 

XXXVII. — On  New  Methods  for  Improving  Splierical  Correction, 
applied  to  the  Construction  of  Wide-angled  Object- 
glasses.    By  Professor  E.  Abbe,  of  Jena,  Hon.  F.R.M.S. 

(IfigO „        812 

XXXVIII. — On   the  Anatomj'   of  Leptodora   hyalina.     By  H.    E. 

Forrest.     (Plates  XXIV.  and  XXV.)       „        825 

XXXIX. — On  a  New   Species  of   the   Genus   Eucampia.    By 

Henry  Stolterfoth,  M.D.     (4  figs.) „        835 

XL. — Immersion  Stage  Illuminator.    By  John  Mayall,  jun., 

F.R3I.S.    (1  fig.)        „        837 

XLI. — On  a  Table  of  Numerical  Apertures,  showiug  the 
Equivalent  Angles  of  Aperture  of  Dry,  Water  Immer- 
sion, and  Homogeneous  Immersion  Objectives,  with  their 
respective  Resolving  Powers,  taking  the  Wave  Length 
of  Line  E  as  the  Basis ;  a  =  n  sin.  u\  n  =  refractive 
index,  and  w  =  ^  anjile  of  aperture.  By  J.  W.  Stephenson, 

F.R.A.S.,  Treas.  R.M.S ,        839 

XLII. — Aperture  Measurements  of  Immersion  Objectives  ex- 
pressed as  "  Numerical  Aperture."  By  John  Mayall, 
jun.,  F.R.M.S „        842 

Record  of  CuBREirr  Researches  belating  to  Ixvertebrata,  Cryptogamia, 
Microscopy,  &c.,  iNCLrDiNG  Embryology  and  Histology  generally. 
( =  Notes  and  Memoranda  in  Nos.  1  to  4) : — 

ZOOLOGY. 

A. — General,  including  Embryology  and  Histology  of  the  Vertebrata.  ^^^^ 

"  Gell-Soul  and  Cellular  Psychology  "          No.  1  53 

The  Striicture  of  Blood-vessels „  82 

Cells  and  their  Vital  Fhenotnena No.  2  137 

Influence  of  the  different  Colours  of  the  Spectrum  on  Ani- 
mals and  Plants        „  138 

Nuclei  of  the  Blood-corpuscles  of  the  Triton       No.  3  272 

Division  of  Cartilage  Cells „  273 

Infltience    of  the    different    Colours   of    the   Spectrum   on 

Animals „  273 

Primitive  Stripe  in  the  Chick        No.  4  395 

Evolution  of   the   Male  and  Fetnale   Genital    Glands    of 

Mammalia i,  397 

Natural  Science  Prizes  of  the  Brussels  Academy        ..      .,  „  397 

Cells  and  Nuclei „  397 

Nucleus  in  Blood'corpuscles No.  5  545 

6  2 


VIU  CONTENTS. 

PACE 

Divisim  of  Cartilage  Cells No.  5  546 

Final  Changes  in  Meckel's  Cartilage „  546 

Histology  of  Nerve-fibre        „  546 

Microscopical  Phenomena  of  Muscidar  Contraction     ..       ..  „  547 
Development  of  the  Olfactory  Nerve  and  Olfactory  Organ  of 

Vertebrates         „  547 

Cell-division  in  Animals       No.  6  692 

Develupmeiit  of  the  Bibs  and  the  Transverse  Processes       . .  „  693 

Connective  Tissue ,,  694 

Sexual  Organs  of  Teleostei „  694 

Evolution  of  the  Embryo  in  Eggs  put  to  incubate  in  Warm 

Water        „  696 

Mechanical  Genesis  of  Tooth  Forms „  696 

Refractive  Powers  of  Animal  Tissues <,  697 

Innervation  of  the  Respiratory  Organs        „  697 

Ovary  and  the  Corpus  Luteum ,,  698 

Natural  Science  Prizes,  Danish  Academy „  699 

Klein  and  Smith's  Atlas  of  Histology           ,,  700 

Gestation  of  the  Armadillo No.  7  844 

Vitality  of  the  Spermatozoa  of  the  Trout „  844 

Experiments  on  Development        „  844 

Granular  Bodies  found  in  the  Ovum „  845 

Development  of  the  Ova  and  the  Structure  of  the  Ovary  in 

Man  a7Kl  other  Mammalia         „  845 

Micro-chemical  Researches  on  Cell-nuclei „  847 

Observations  on  the  Living  Cartilage  Cell „  847 

Microcytes  (very  small  Red  Blood-corpuscles)  in  the  Blood  „  847 

Terminal  Nerve-plexus  in  the  Cornea          „  848 

Harderian  Gland  of  the  Duck      „  848 

Structure  of  the  "  Eye-spots  "  of  some  Osseous  Fishes       ,..  „  849 

Histology  of  the  Cerebellum  of  Petromyzon  fluviatilis         . .  „  850 

Spinal  Ganglia  and  Dorsal  Medulla  of  Petromy ton    ..       ..  ,,  851 

Amoeboid  Epithelia         „  852 

Effects  of  Induced  Currents  on  the  Nervous  System  ..      . .  „  853 

B. — Inveetebrata. 

The  Stnwture  of  the  Nerves  in  the  Invertebrata         ..      ..  No.  1  76 

Brain  of  Invertebrates No.  2  142 

Formation,  Fructification,  and  Division  of  the  Animal  Ovum 

{in  Echinoderms,  Worms,  Ccelenterates,  and  Molluscs)    . .  No.  3  274 

Digestion  of  Albuminoids  by  Invertebrata ,,  274 

Invertebrates  of  Kerguelen's  Land       No.  4  398 

Digestive  Ferments  of  the  Invertebrata        No.  5  548 

Fauna  of  Kerguelen's  Land         No.  6  700 

Deep-water  Fauna  of  the  Lake  of  Geneva „  700 

"  Liver"  of  the  Invertebrata        „  701 

Mollusc  a. 

The  Termination  of  the  Visceral  Arterioles  in  Mollusca    ..  No.  2  164 

Hamocyanin,  a  new  Substance  in  the  Blood  of  the  Octopus  „  164 

Chromatic  Function  in  the  Octopus      „  165 

Parasites  of  the  Lamellibranchiata      No.  3  285 


CONTENTS.  IX 

PAGE 

Eye  of  the  LamellibrancMata       No.  3  303 

Fvot  of  the  Unionidm „  303 

*' Digger"  Mollusc  and  its  Parasites „  303 

Hermaphroditism  in,  and  the  Spermatophores  of  the  Nephro- 

pneustous  Gasteropoda      „  304 

Mucous  Threads  of  Limax ,,  30+ 

Blood-cells  of  the  Acephala  .,      No.  4  398 

Later  Stages  in  the  Development  of  Fresh-water  Mussels   ..  „  309 

Docomotion  of  the  Terrestrial  Gasteropoda ,,  399 

Auditory  Organs  of  the  Heteropoda      ,,  401 

Peculiarity  in  Littorina        ,^  401 

Structure  and  Physiology  of  the  Octopus ,  402 

Neomenia  and  tJie  other  Amphineura „  404 

Anatomy  of  Chiton        „  404 

Phenomena  which  precede  the  Segmentation  of  the  Ovum  in 

Helix  aspersa „  40.j 

Liver  and  Digestion  of  the  Cephalopodous  Mollusca    .,      .,  „  40.5 

New  Facts  in  the  Anatomy  of  Molluscs        No.  5  548 

Generative  Organs  of  the  Cephalopoda         „  5 19 

Observations  on  the  Organization  of  Solenopus „  5.50 

Organ  of  Bojan'is  in  Anodon        „  551 

Chromatophores  of  the  Cephalopoda No.  6  701 

Shells  of  the  Cephalopoda  in  relation  to  the  Body  of  their 

Constructor        „  703 

Eye  of  the  Cephalopoda         „  705 

Action  of  Strychnine  on  Gasteropodous  Molluscs         ..      ,,  „  705 

Animal  of  Voluta  musica      „  706 

Neomenia  (^Solenopus) „  70G 

Ttfo  Collections  of  Pteropoda       „  706 

Eespiratory  Apparatus  of  Ampullaria         „  706 

Habits  of  the  Octopus No.  7  854 

Segmentation  of  the  Ovum  in  Helix  aspersa        „  854 

Cutaneous  Absorption  of  Helix  pomatia       „  856 

Lnfluence  of  "  Cardiac  Poisons  "  on  Helix  pomatia      . .       . .  „  857 

Pespiratory  Apparatus  of  Ampullaria         ,,  857 

Doridce  of  the  Northern  Seas        „  859 

Glaruls  in  the  Foot  of  the  LamellibrancMata        „  859 

Land  Shells  of  Californian  and  Mexican  Ishuuls        ..       ..  ,,  861 

Pompeian  Conchology „  861 

Method  of  Obtaining  Minute  Mollusca         „  861 

Segmentation  in  Worms  and  Pulmonates „  877 

Mollusc  oida. 

The  Relations  of  Rhabdopleura No.  1  84 

Development  of  Polyzoa       No.  3  300 

Presence  of  a  Segmental  Organ  in  the  Endoproct  Polyzoa  „  301 

Power  of  Locomotion  in  the  Tunicata „  302 

Extension  of  the  coiled  Arms  in  Bhynchonella „  302 

New  Tunicata       No.  4  407 

Development  of  the  Salpidce No.  5  551 

Affinities  of  the  Polyzoa       „  553 


CONTENTS. 

PAGE 

Loxosoni't      No.  5  553 

Barbed  Hooklets  on  Spines  of  a  Brachiopod        „  553 

Kew  Genus  of  Polyzoa         No.  6  707 

Embryology  of  Tendra  zostericola        „  707 

Bccent  Species  of  Heteropora       No.  7  862 

Cyphonantes          „  863 

Arthropoda. 

The  Form  of  the  Crystalline  Cones  in  the  Arthropod  Eye  ,.  No.  1  56 

Structure  of  the  Cerebrum  and  Retina  in  the  Arthropoda  ..  No.  5  554 

a.  Insecta. 

Besearches  on  the  Proboscis  of  Butterflies No.  1  41 

New  (^Auditory')  Sense-organs  in  Insects.     (Plate  IV.')     ..  „  45 

Post-embryonic  Formation  of  Appendages  in  Insects  . .      ..  „  55 

M(dpighian  Vessels  of  Insects      ,,  60 

Parthenogenesis  in  Bees        „  88 

Poison  Apparatus  and  Anal  Glands  of  Ants       No.  2  142 

Parthenogenesis  in  Bees        „  143 

Hermaphroditism  in  Perlidoi        ..       ,.      „  144 

Parthenogenesis  in  Bees       No.  3  297 

Spinning  Glands  of  the  Silkworm „  297 

Odoriferous  Cells  in  Lepidoptera „  298 

Seasonal  Dimorphism  of  Lepidoptera „  298 

Development  of  Podurella „  299 

Respiratory  Organs  of  the  Larva  of  Cidex „  299 

Sucking  Plate  of  Dytiscns „  300 

Gull-making  Ap)hides No.  4  407 

Buzzing  of  Insects        „  408 

Larval  Cases  of  Phryganeidoe       „  408 

Development  of  the  Silkworm       ..      ..• „  409 

Venomotis  Caterpillars „  411 

Abortion  of  the  Hairs  on  the  Legs  of  certain  Caddis-flies,  ^-c.  „  412 

Comparative  Embryolo:iy  of  the  Insecta       „  413 

Formation  of  the  Blastoderm  and  of  the  Germ-layers   in 

Insects       No.  5  554 

Mode  of  Recognition  among  Ants         „  555 

Toilet  Habits  of  Ants „  556 

Malformation  in  an  Insect „  558 

Parasitic  Insects „  558 

Notes  on  Phryganea: „  558 

Habits  and  Intelligence  of  Vespa  maculata ,,  559 

Metamorphoses    of  the  Blister  Beetle    (^Lytta  vesicatoria, 

Fab.)          No.  6  708 

New  Genus  of  Cochineals  of  the  Elm „  709 

Notes  on  the  Phryganida      „  710 

Nervous  System  of  Insects No.  7  863 

Cephalic  Ganglia  of  the  Insecta „  864 

Brain  of  the  Cockroach         „  864 

Nerves  of  the  Proboscis  of  Diptcra       „  865 

Sense-organs  of  Insects         „  865 

Scales  of  the  Lepidoptera „  866 


CONTENTS.  XI 

PAGB 

Butterflies  with  Dissimilar  Sexes         No.  7  867 

Adoption  of  an  Ant-quecn „  868 

Mode  of  depositing  Ant-eggs         „  868 

)3.  M3rriapod.a. 

Poismi  Glands  of  the  Centijyedes No.  1  57 

Organization  of  Myriapoda No.  3  295 

Folyxeniis  lagurus,  Be  Geer         „  296 

Tracheal  System  of  Glomeris       No.  4  414 

Observations  on  Peripatus No.  5  559 

Anatomy  and  Physiology  of  the  Digestive  Organs  of  the 

Myriapoda         No.  6  710 

New  Scolopendra „  712 

New  Pawopod      No.  7  869 

y.  Arachnida. 

British  Acari — Orihatidue No.  1  76 

Degeneration  of  the  Visv/xl  Organs  in  Arachnida       ..      ..  No.  2  146 

Natural  Classification  of  the  Spiders No.  3  293 

Besearches  into  the  Developmental  History  of  the  Spiders , .  „  294 

Neio  Genus  of  the  Chelifcridce      „  295 

New  Acarina         „  295 

Structure  of  the  Hydrachnida      No.  4  415 

Acarina  found  parasitic  in  the  Cellular  Tissues  and  Air- 
sacs  of  Birds     ,,  415 

On  some  Genera  of  Acarina „  417 

Parasitic  Chyletidw       „  418 

Basilica  Spider  and  her  Snare.     (1  fig.) No.  5  559 

Aeronautic  Flight  of  S/nders        „  561 

New  and  other  Pycnogonida „  562 

Pentastoma  tanioides  in  the  Ear  of  a  Dog No.  6  712 

Genera  of  Acari   ..       ..       ..      ..       „  712 

New  Division  of  the  Tarantulida          No.  7  869 

Differences  between  the  Young  and  the  Adtdt  Forms  of  the 

Gamasidas          „  870 

Pairing  of  Spiders         „  870 

Observations  on  the  Pycnogonida          „  870 

5.  Crustacea. 

Parasitic  Crustacea      No.  1  61 

Formation  of  Ovisacs  in  Copepoda        „  85 

Phosphorescence  of  the  Flesh  of  Jjobsters No.  2  151 

Species  of  Marine  Crustacea  in  Lake  Erie „  152 

Gigantic  Isopod  of  the  Deep  Sea „  152 

Limicoloris  Cladocera ,,  153 

Kidney  of  the  Fresh-v-ater  Crayfish No.  3  291 

Action  of  the  Heart  of  the  Crayfish ,,  292 

Intimate  Structure  of  the  Central  Nervous  System  of  Deca- 

podous  Crustacea      No.  4  419 

Functions  of  the  Ganglionic  Chain  in  the  Decapodous  Crus- 
tacea   „  419 


Xll  CONTENTS. 

PAGE 

Male  Organs  of  the  Decapodons  Crustacea No.  4  420 

Central  Nervous  System  of  the  Crayfish      „  422 

Heart  of  the  Crai/fish  and  Lobster       „  423 

New  Branchiopoda  of  the  French  Coasts „  424 

On  the  Crustacea  of  the  Mozambique „  425 

Form  of  the  Muscular  Contraction  in  the  Crayfish     ..      . .  No.  5  562 

Amphipn  and  Pohjcheles  ( Willemoesid)       „     ■  563 

Life-history  of  the  Bopyridce       ».       . .  „  563 

The  Nehaliad  Crustacea  as  Types  of  a  New  Order     ..      ..  No.  6  713 

Physiology  of  the  Nervous  System  of  the  Crayfish       ..      ,.  „  713 

Influence  of  Heat  on  the  Nervous  Centres  of  the  Crayfish,.  „  714 

Blood  of  the  Lobster „  715 

Observations  on  the  Amphipoda ,,  715 

Contributions  to  the  Natiiral  History  of  the  Caprellidoe     .,  „  715 

Caprcllidiv  of  the  Mediterranean „  716 

Organization  of  the  Phronimida „  717 

Glands  found  in  the  Appendages  of  the  Phronimida  ..      ..  „  719 

"  House"  of  the  Phronimida        „  719 

Some  young  Stages  of  Penceus  Caramote „  720 

Hermaphroditism  of  the  Isopoda „  720 

Asellus  cavriticus „  721 

New  Peltidia          „  722 

Structure  of  the  Nervous  System  of  the  Decapodous  Crus- 
tacea            No.  7  872 

Physiology  of  Muscle  aiid  Nerve  in  the  Lobster „  872 

Action  of  Electric  Currents  on  the  Pincer  of  the  Crayfish  ..  „  873 

Atlantic  Stalk-eyed  Crustaceans „  873 

Some  New  Cymothoida „  874 

Trilobites  and  Limuli „  874 

New  Species  of  Chiroccphalus       „  874 

Reproductive  Organs  of  Non-parasitic  Copepoda         .,      . .  •  „  875 

The  Notodelphyidce       ^^  876 

New  British  Entomostraca „  877 

Vermes. 

The  Tomopteridm No.  2  1.55 

Abnor)nal  Sexual  Organs  in  the  Horse  Leech      „  156 

A  New  Rotifer — Anuraa  longispina.     {^  fig.) „  157 

Trichina:        ^^  159 

Trichina-phobia  at  Berlin 159 

Function  of  Chlorophyll  in  the  Green  Planarice „  161 

Development  and  Metamorphoses  of  Ta:nice „  162 

Helminthology        No.  3  283 

Excretory  Apparatus  of  Solenophorus  tnegalocephalus       . ,  „  284 

Anatomy  and  Embryogeny  of  the  Tamiadce „  285 

Parasites  of  the  Lamellibranchiata      „  285 

New  Turbellarian          286 

Digestive  Organs  of  the  Fresh-water  Turbellarians     ..      ..  „  287 

Land  Planarians 288 

Marine  Planarians        ,  288 

Organization  and  Devdojmicnt  of  the  Oxyunds ,  289 


CONTENTS.  Xlll 

PAGE 

Researches  on  Bvncllia  viridis      No.  3  290 

Development  of  Chcctopoda „  291 

Parasitism  of  Notommata  011  Vaucheria       „  291 

Pneumonia  produced  by  a  Filarian  Worm    ..       No.  4  425 

On  Sagitella  (^Wagner)         „  425 

Development  of  the  Annelides ..      ..  No.  5  563 

Anatomy  of  Magelonn „  567 

Arrangement  of  the  Nerve  Cords  in  the  Annelides ,  569 

Gills  of  Serpula „  570 

New  Annelides  from  the  Philippines „  571 

Trichinosis  in  a  young  Hippopotamus ,»  571 

New  Diseases  of  Hot-house  Ruhiacece „  572 

Female  Organs  of  Echinorhynchus       ,,  572 

Jensen's  Twhellarian  Worms  of  Norway ,  573 

Reproductive  Organs  of  the  Marine  Ectoparasitic   Trema- 

toda )5  573 

Organization  of  Axine  and  Microcotyle        ,;  574 

Life-history  of  the  Tape-  Worm  of  the  Shrew      „  575 

New  Species  of  Tenia No.  6  722 

Notes  on  the  Turhellaria       »  723 

Studies  on  the  Nemertinea u  723 

Histology  of  Convoluta  Schulzii „  725 

Planaria  Limuli ■,■>  727 

Classification  of  the  Monogenetic  Tremiitoda       „  728 

Entopat-asitic  illarine  Trematodes        „  728 

Helminthological  Studies ..  >,  729 

Ascari^  parasitic  in  the  Lion        >,  729 

Ascaris  of  the  Orang-  Outang       ■,,  729 

Filaria  Otarice       »  729 

Muscle-cells  of  the  Nematoids       n  729 

Further  Studies  on  the  Oligochceta       „  729 

Spermatophores  of  the  Earth-worm      „  730 

Body-cavity  of  the  Sedentary  Annelids  and  their  Segmental 

Organs      »  731 

Segmental  Organs  of  the  Capitellidas „  733 

Lateral  and  other  Goblet-shaped  Organs  of  the  Capitellida:  „  734 

Segmentation  in  Worms  and  Pulmonatcs No.  7  877 

Prizes  for  Life-histories  of  Entozoa „  878 

Development  and  Metamorphoses  of  Tainia; „  878 

Nematodes  in  the  Caves  of  Camiola „  878 

Anurma  longispiiui         <,  879 

Studies  on  the  Gephyrea       „  879 

Pelagic  Annelids  from  the  Canary  Islands          ,,  883 

Annelid  Jaws  from  Scotch  and  Canadian  Pcdasozoic  Rocks  „  884 

Organization  of  Batrachohdella  Latasti,  C.  Vig „  885 

New  Alciopid         ,,  886 

Organization  and  Classification  of  the  Orthonectida    .,       ..  ,,  886 

Echinodermata . 

Splines  of  Echini No.  2  171 

New  Genus  of  Starfishes       No.  3  283 


xiv  CONTENTS. 


Emhryogcny  of  Asteriscus  vcrruculatus       No.  4  428 

On  the  Skeleton  of  the  Asteriadce          „  428 

"  Comet-forms  "  of  Starfishes       No.  5  576 

Genital  Organs  of  Asterina  gibhosa      „  579 

Anatomy  of  Brisinga „  579 

Aspidura        „  581 

Anatomy  of  the  Ophiurida No.  6  737 

Aspidura       ,,  738 

Comatulce  of  the  '  Challenger '  Expedition „  739 

New  Organs  of  the  CidaridcB        ..      .. No.  7  888 

Echini  of  the  '  Challenger ' „  889 

Anal  Plates  of  Echinocidaris        „  890 

Ccelenterata. 

Origin  of  the  Sexual  Products  in  Ilydroids         No.  1  66 

New  Anthozoa       „  87 

Parasitism  of  a  Coral  on  a  Sponge      „  96 

J7ie  Locomotor  System  of  Medusce       No.  2  171 

Tetrapteron  volitans      „  172 

Deep-sea  Siphonophora          No.  3  278 

Strange  Anomaly  among  the  Hydromedxisoi         „  278 

Muscle-epithelium  in  Anthozoa ,,  279 

Phylogeny  of  the  Antipatharia „  279 

Skeleton  of  the  Alcyonaria „  279 

New  Species  of  Isis „  281 

Gorgonia  verrucosa        „  281 

Prehensive  Cells  in  the  Ctenophora      „  282 

Australian  Corals          „  282 

New  Genus  of  Millcporida: „  283 

Researches  into  the  Hydrozoa       No.  4  430 

Spongicola  fstidar is,  a  I/ydroid  inhabiting  Sponges    .,       ..  „  431 

Deep-sea  Siphonophora          „  432 

Histological  Characters  and  Development  of  Myriothela      , .  „  432 

Classification  and  Phylogeny  of  Actinozoa No.  5  581 

Neio  Paludicolous  Medusa „  582 

Charybdea  marsupialis „  583 

Halistemma  tcrgestinum        „  584 

Tubularia  mesembryanthemum „  585 

New  Genera  and  Species  of  Corals       No.  6  741 

Ctenophora  of  the  Gulf  of  Naples        „  742 

Phylogeny  of  the  Ctenophora         No.  7  890 

Zoantharia  malacodermata  of  the  Coasts  of  Marseilles       . .  ,,  892 

Blastology  of  the  Corals       „  892 

Porifera. 

The  Fibrilla:  of  Filifera                 No.  1  49 

Sperm-formation  in  Spongilla        „  73 

Borings  of  a  Sponge  in  Marble „  82 

Parasitism  of  a  Coral  on  a  S^oonge       „  96 

Development  of  Spongilla  fluviatilis      No.  2  174 

Morphology  and  Systematic  Position  of  the  Spongida          .,  „  177 


CONTENTS.  XV 


PAGE 


Sponje  Spicules  (1  fig.)        ^O- 2  1^7 

Spomiwola  fishdaris,  a  Hydroid  inhahitimj  Sponges     ..      ..    No.  4  431 

Structure  of  the  Aplysinidce         » 

Structure  of  Spongelia " 

Spongiological  Studies           No.  7  894 

Development  of  Horny  Sponges >,  897 

Protozoa. 

Contributions  to  our  Knowledge  of  the  Protozoa          ,.      ..    No.  1  42 

T/ie  Generation  of  Gas  in  the  Protoplasm  of  living  Protozoa       „  72 

1  he  Organs  of  Attachment  of  Stentors        „  83 

The  Morphology  of  the  Oxytrichina „  91 

Parasitism  amongst  Infusoria      .>  9^ 

Gloidiiim,  anew  Genus  of  Protista     No.  2  179 

Flagellated  Organisms  in  Bats' Blood „  190 

Heprodu  tion  of  Noctiluca »  195 

Eoioon  Canadcnse         ..      ..      No.  3  275 

Beticularian  Rhizopoda         »  276 

Protozoa  of  Northern  Russia       ,.  276 

Evolutionof  the  Infusoria  from  the  Lower  Protozoa..       ..    No.  4  438 

Acineta;  and  Vorticellw        ?j  ^''^ 

Researches  on  the  AcimtiC )>  '^'^^ 

The  NoctiluccB       »»  ^^^ 

Flagelhim  of  Euglena  viridis        »  4^  1 

Anomalies  in  the  Development  of  the  Lowest  Organisms     ..        „  446 

Tmtinnus  scmiciliatus,  a  new  Infusor          No.  5  587 

Blepharisma  lateritia »  ^°° 

Haptophrya  gigantea,  a  new    Opalinid  from  the  Intestine 

of  the  Anowo-us  Batrachia        »  588 

Steinh  '  Organismus  der  Infusionsthicre ' „  590 

Effect  of  Light  on  Pelomyxa        ,.  591 

Eozoon  Canadense         No.  6  744 

Peridinium  and  Gymnodinium v  745 

Reticularian  Rhizopods         No.  7  897 

Structure  of  Haliphysema  Tumanowiczii „  898 

Observations  on  New  Infusoria >>  899 

Influence  of  the  different  Colours  of  the  Solar  Spectrum  on 

Infusoria "  •'^^ 

Supposed  new  Fresh-v:atcr  species  of  Freia         ,,  900 

Lithamceba  discus,  a  new  Rhizopod      »  900 

New  Moneron.     iPlate  XXVI.)          „  901 

Eozoon  Canadense        »  902 

Fertilization  of  Red  Algce  by  the  Agency  of  Infusoria        ..       „  932 

BOTANY. 

A.— General,  including  Embryology  and  Histology  of  the  Phanerogamia, 

The  Ovule      No.  1  49 

Sir  Joseph  Hooker  on  the  Modern  Development  of  Micro- 
botany        I)  "' 

New  Classification  of  the  Vegetable  Kingdom      „  90 

Injlttence  of  the  different  colours  of  the  Spectrum  on  Animals 

and  Plants        Nu.  2  138 


XVI 


CONTENTS. 

Page 

Ascent  and  Circulation  of  the  Sap       No.  2  147 

Growth  of  the  Root  of  Phanerogams    ..      „  149 

Chlorophyll ,>  161 

Development  of  the  Embryonal  Sac      No.  3  305 

Protein-crystalloids       „  306 

Composition  of  Chlorophyll „  306 

Natural  Science  Prizes  of  the  Brussels  Academy        . .       . .    No.  4  397 

Chemical  Composition  and  Function  of  Leaves „  442 

Fermentation  in  the  Tissues  of  Plants         „  442 

Assimilation  of  Soda  by  Plants „  443 

Nutrition  of  Phanerogamic  Parasites „  444 

Polyembryony,  true  and  false,  and  its  relation  to  Partheno- 


genesis 


444 


Permeability  of  Pellicle  Precipitates No.  5  592 

Origin  of  Chlorophyll-grains        „  592 

Heliotropism  of  Plants         „  593 

Symbiosis       jj  594 

Is  the  Ovule  an  Axial  or  a  Foliar  Structure  ? ,  594 

Starch-tramforming  Ferments ,.  595 

Tannin  in  Vegetable  Cells „  595 

Functions  of  Vessels „  596 

Natural  Science  Prizes,  Danish  Academy No.  6  699 

Division  of  the  Pollen-grain  in  Angiosperms       „  746 

Anatomical  and  Physiological  Study  of  Nectaries       ..      ..  „  748 

Causes  of  the  Change  in  Form  of  Etiolated  Plants      ..      ..  „  749 
Effects  of  Submersion  on  Aerial  Leaves,  and  of  Water  on 

Floating  Leaves         „  750 

Absorption  of  Water  by  the  Lamina  of  Leaves ,,  750 

Movements  of  Growing  Leaves  and  Petals „  751 

Disengagement  of  Heat  which  accompanies  the  Expansion 

of  the  Hale  Inflorescence  of  Dioon  edule „  752 

Spiral  Cells  in  the  Root  of  Nuphar  advenum      „  752 

Structure  of  the  Fruit  of  Coninm  macidatum      „  752 

Modifications  which  Starch  undergoes  from  a  Physical  Point 

of  View      „  752 

Rain  of  Sap „  753 

Development  of  the  Embryo  of  Phanerogams      No.  7  902 

Development  of  the  Embryo-sac  of  Angiosperms         ..       ..  ,,  903 

Angiosperms  and  Gymnosperms           „  905 

Nucleus  of  the  Embryo-sac „  907 

Gymnospermy  of  Conifers „  907 

Reproductive  Organs  of  Cycadece         „  908 

True  Mode  of  Fecundation  of  Zostera  marina „  908 

Arrangement  and  Growth  of  Cells       „  908 

Vari(ms  Forms  of  the  Cell-nucleus       „  909 

Condmting  Tissue  for  the  passage  of  Pollen-tubes       ..      .,  „  910 

Seminal  Integuments  of  Gymnosperms         „  911 

Relationship  of  Intercellidar  Spaces  to  Vessels           ..       ..  „  912 
Peculiarities  in  the  Power   of  Living  Parts  of  Plants  to 

conduct  Electricity ,,  912 

Influence  of  Electricity  on  Vegetation         „  912 


CONTENTS.  XVll 

PAGE 

Absorption  of  Rain  and  Dew  by  the  Green  Parts  of  Plants  No.  7  913 
Decrease  of  the  Power  of  Absorption  in  Branches  dipped 

in  Water )>  913 

Water-p)ores          »  913 

Respiration  of  Plants            „  914 

Respiration  of  Marsh  and  Water  Plants „  915 

Influence  of  Light,  Warmth,  and  Moisture  on  the  Opening 

and  Closing  of  the  Anthers  of  Bulbocodium  vernum        ..  „  915 

Chemical  Researches  on  the  Formation  of  Coal „  915 

New  Carbo-hydrate        „  916 

Calcium  phosphate  in  the  Living  Cells  of  Plants        ..      ..  „  916 

B. — Ckyptogamia. 

Microbia         No.  1  58 

New  Cryptogamic  Journals No.  2  154 

New  Classification  of  Thallophytes        „  166 

Action  of  Light  and  Heat  on  Swarmspor-es  (^Zoospores)     . .  No.  3  307 

Luerssen's  Handbook  of  Cryptogamic  Botany      No.  4  445 

Anomalies  in  the  Decelopment  of  the  Lowest  Organisms     . .  „  446 

Influence  of  Light  on  the  Movements  of  Mobile  Spores        . .  „  447 

Entopihytic  and  Entozoic  {parasitic)  Species  of  Cryptogams  „  448 

Cryptogamia  Vascularia, 

The  Early  Development  of  EquisetacecB     ' No.  2  157 

Organogenic  Researches  on  the  Capsule  of  Mosses,  and  on 

the  Embryo  of  some  Polypodiacea: „  159 

Arrangement  of  the  Cells  in  the  flat  Prothallia  of  Ferns  . .  No.  3  317 
Apogamous  Ferns   and   the   Phenomenon   of  Apogamy  in 

general       >,  317 

Apogamy  in  Isoetes       ,,  319 

Germination  of  the  Schiiceacece No.  4  451 

Embryology  of  Vascular  Cryptogams No.  5  596 

Adventitious  Buds  in  Ferns „  597 

Production   of   the  first    Vegetative   shoot    of    Equisetum 

palustre )>  597 

Pi-othallium  of  Salvinia  natans No.  6  753 

G ermination  of  Fern-spores No.  7  916 

Bilateralness  of  Prothallia „  917 

'  Development  of  the  Prothallium  of  Salvinia        „  918 

Muscineee. 

Organogenic  Researches  on  the  Capsule  of  Mosses,  and  on 

the  Embryo  of  some  Pol  i/podiacece No.  2  159 

Nostoc-colonies  of  Anthocerotece            „  187 

Origin  of  Tubes  in  the  Nostoc-colonies  in  Blasia         ..       ..  No.  5  598 

New  Bryum No.  7  919 

Parasitism  of  Lichens  on  Mosses          „  930 

Characeae. 

Homology  of  the '^Nucule*' of  Char acece No.  3  317 


Xviii  CONTENTS. 

Fungi. 

PAGE 

Lichens,  Bacteria,    Bacillus    Onjanisms,  and    the  Lowest 

Forms  of  Life No.  1  G9 

Alcoholic  Fermentation         „  82 

The  Conidia  of  Polyporus  siilfurcus,  and  their  Development  „  85 

Fungoid  Diseases  of  Plants No.  2  167 

Organization  of  Hyijrocrocis  arscnicus,  Breh „  169 

The  "  Blast  ids"  of  the  Loicer  Flaiits „  170 

Alcoholic  Fermentation „  187 

Bacteria  in  the  Boison  of  Serpents       „  189 

Luminous  Bacteria  in  Meat          No.  3  310 

Influence  of  Ligld  on  Fungi „  314 

Spores  on  the  upper  side  of  the  Fileus  in  Hymenomycetes  . .  „  314 

Change  of  Colour  in  the  S2)ores  of  Fungi „  315 

Fungi  found  within  the  Shell  of  the  Egg      „  315 

Fungi  parasitic  on  the  Cabbage „  315 

Fungus  Disease  in  Lettuces  (^Peronospora  gangliiformis)    ..  „  316 

Fmtgi  of  Stalactites      „  316 

Conidial  Fructification  of  Fumago        „  316 

Belationship  of  Oidium  albicans  and  Mycoderma  vini          . .  No.  4  453 

Alcoholic  Fermentation „  453 

Exp)eriinental  Researches  on  a  Leptothrix „  454 

Sexuality  of  the  Ascomycetes        „  454 

Bolymorphism  of  Agaricus  melleus       „  455 

Conidia  of  Fistulina  hepatica        „  456 

Endophytic  Fungiin  Follen-grains      No.  5  598 

Bate   of    Germination   of    Fxingus-spores   and   Growth   of 

Mycelium „  599 

New  parasitic  Bhycomycete „  599 

The  "  Carolo  vero  "  and  "  Carolo  bianco  "  of  the  Rice         . .  „  600 

Sporormia,  a  Subgenus  of  Sphxria       „  600 

Sclerotium  Oryzm         „  600 

Structure  of  Dcpazeacea;      „  601 

Two  New  Vine-1'arasitcs      ,,  601 

Formation  of  Conidia  by  a  Bacillus      „  602 

Fermentation  of  Cellulose „  602 

Resistance  of  Germs  to  a  Temperature  of  100°  C.      ,.      ..  „  602 

Contribution  to  the  Germ  Theory         No.  6  754 

Nature  of  the  Fur  on  the  Tongue „  756 

Supposed  Amylaceous  Substance  in  Fungi „  757 

Cellules  en  boucle ,,  758 

Anthracnose  of  the  Vine        „  758 

Aschotricha „  758 

Development  of  Sclerotia       „  758 

New  Genus  of  Sphceriacem „  759 

Specific  Differences  amo7ig  the  Uredinece      ,,  759 

Ncovossia,  a  New  Genus  of  Ustilaginece      ,,  760 

Injection   of  Bacteria  into   the  Blood  icithout  any   Toxic 

Effects        ,  700 

Anthrax  and  its  Cause „  760 

Structure  of  Cheetondum      No.  7  919 


CONTENTS.  XIX 

PAGE 

Proposed  New  Genus  of  Fungi— Peniophora       No.  7  920 

Vine  Fungi »  ^^0 

Propagation  of  Cluster-cups         »  920 

Onion-smut,  Urocystis  Cepidce      »  9-1 

Lagenidium  RahenJiorstii,  a  new  Phycomycete „  921 

Protonvjces  graminicola         >)  9-4 

Conidial  Fructification  in  Mucorini      „  922 

Beech  Disease,  Phytophfhora  Fagi      „  923 

Berggrenia — Nevi  Genus  of  Discomycetes „  923 

Microphytes  in  the  Blood  and  their  relation  to  Disease        . .  „  924 
Crenothrix  polyspora,    the  Cause  of  the   Unwholesonicness 

of  the  Berlin  Water          „  925 

Fungi  Parasitic  on  Fungi „  926 

Poison  of  Marsh  Fever         »  926 

Development  of  Bacteria       jj  927 

Experimental  Researches  on  a  Leptothrix ,,  928 

Antidote  to  Bacteria-poisoning  in  Frogs       ,,  928 

Sugar-refining  Gum,  Leuconostoc  mesenteroides           ..      ..  „  928 

Excrescences  on  the  Root  of  the  Alder         „  929 

liiclienes. 
Lichens,    Bacteria,   Bacillus    Organisms,   and   the    Lowest 

FormsofLife No.  1  69 

Development  of  Cephalodia  on  Lichens         „  78 

Relation  of  Lichens  to  Algce  and  Fungi       No.  3  311 

Observations  on  Microgonidia        No.  5  603 

Leightons  Lichen  Flora       ..  604 

Microscopical  Slides  of  Lichens „  604 

Lichenological  Review No.  6  760 

Vitricole  Lichens  and  the  Schioendenerian  Hypothesis        . .  No.  7  929 

Parasitism  of  Lichens  on  Mosses          „  930 

Colorific  Properties  of  Lichens „  930 

Microgonidia         m  931 

Algae. 

Lichens,    Bacteria,   Bacillus    Organisms,   and  the   Lowest 

Forms  of  Life  ..       , No.  1  69 

TJie  Sexvxil  Process  in  Diatoms „  93 

Germination  of  the  Spores  of  Yolvox  dioicus       „  95 

The  AUjLC  of  the  White  Sea         No.  2  173 

Life-History  of  the  Diatomacece j?  181 

Movements  of  Diatoms  and  Oscillatoriea; „  182 

Discosporangiiim,  a  New  Genus  of  Phoiosporea; ,,  186 

Reproduction  of  Uloaceoe      »,  186 

Nostoc-colonies  of  Anthocerotece „  187 

Parasitism  of  Notommata  on  Vaucheria      No.  3     291 

Floating  Alga  forming  Scum  on  tJie  Surface  of  Water      ..  „  310 

Thuret  and  Bornefs  '  Phycological  Studies'       „  311 

Morphology  and  Biology  of  tJie  Phycochromacex        . .      . .  No.  4  456 

Halosphcera,  a  New  Genus  of  Unicellular  Algce.    {Plate  XVL.)    „  458 

Black  Mildew  of  Walls         ,  459 


XX  CONTENTS. 

PAGE 

Conjugation  of  Swarmspores  of  Chroolepus         No.  5     601 

Structure  and  Mode  of  Beproduction  of  Cutler iacex  ..       ..  „  605 

New  Pai-asitic  Alga       „  606 

Siphonocladaccm,  a  New  Group  of  Green  Algm „  606 

Besting  Condition  of  Vaucheria  geminata „  607 

Italian  Algce         „  607 

Suhalpine  Desmidiece „  607 

Algce  from  Lake  Nyassa,     (3  figs.) „  608 

Thallus  of  the  Diatomacem „  608 

Systematic  Position  of  the  Volvocinem         „  609 

Power  of  Algce  to  resist  Cold        No.  6     761 

Marine  Algce  of  the  Gulf  of  Naples      „  762 

New  Diatoms         „  762 

Terrestrial  Diatoms „  762 

Formation  of  the  Siphons  and  Tetraspores  in  Pohjsiphonia  No.  7     932 

Fertilization  of  Red  Algce  by  the  Agency  of  Infusoria        . .  „  932 
Cell-structure  of  Griffithsia  setacea,  and  Development  of  its 

Antheridia  and  Tetraspores      ,,  934 

Reproduction  of  Cutleria       ,,  934 

Conjugation  of  Ectocarpus „  935 

American  (Edogoniacece         „  935 

New  Genus  of  Chroolepidce „  936 

Fossil  Algce  belonging  to  the  Verticillate  Siphonece       ..       ..  „  936 

Influence  of  Light  on  the  Movements  of  Desmids        ,.      ,,  „  937 

New  Diatom „  937 

Adulteration  of  Currant  Jelly  ivith  Diatoms        „  938 

Palmelline,  the  Colouring-matter  of  Palmella  cruenta         . .  „  938 

Mycoidea parasitica,  a  new  Parasitic  Alga          „  938 

Two  new  Parasitic  Algce       „  939 

Method  of  Cultivating  Vohox  globator        „  939 


MICKOSCOPY,  &c. 

Cuchineal  for  Staining No.  1        43 

44 
52 
52 
55 
59 
59 
62 
65 
71 
72 


Prazmowski's  Heliostat.     (1  fig.)  

Laboratory  for  Microscopic  Work        

A  New  Micrometer        

The  Weber  Slide.     (I  fig.) 

Orchella  as  a  Staining  Material 

Construction  of  Eye-pieces 

Iinpj'ovements  in  Micro-photography 

Measure  for  Covering-glass.     (3  figs.)         

Method  of  representing  an  Object  from  Microscopic  Sections 

Microscopy  at  the  Paris  Exhibition      

The  Exact  Orientation  of  the  principal  Section  of  Nicols  in 

Polarizing  Apparatus       „  74 

Improvements  in  Object-glasses.     (1  fig.) „  75 

Mr.  Sorby's  New  Micro-spectroscope „  81 

Dry  Preparations  of  Diatoms,  4'c „  83 

A  New  Method  of  Preparing  a  Dissected  Model  of  an  Insect's 

Brain  from  Microscopic  Sections      „  84 


CONTENTS.  XXl 

PAGE 

Polarizer  for  the  Microscope '       No.  1  87 

Microscopical  Injection  of  Molluscs      ,>  9i 

Microscopy  at  the  American,  Association  for  the  Advancement 

of  Science ,■,  95 

Picro-carmine  for  Cell-nuclei        No.  2  138 

Colonel  Woodward  on  the  Oil-Immersion  Objectives  and  the 

Apertometer      „  140 

Diffraction  Experiments  with  Pleurosigma  angulatum        ..  „  141 
Employment  of  Mixtures  of  Chromic  and  Osmic  Acids  for 

Histological  Purposes        „  144 

Microscopical  Research  under  Difficulties „  145 

Removal  of  Air  from  Microscopic  Specimens        „  150 

Immersion  Illuminators         „  151 

Unit  of  Micrometry      „  154 

The "  Micro-Megascope "      „  160 

Another  Method  of  Staining         „  163 

Size  of  Society  Screv:  and  of  Slides     „  163 

Staining  for  Fungi        „  170 

Achromatic  Lenses        „  173 

Preparation  of  Microscopic  AqvMic  Anim/xls ,  180 

The  Postal  Microscopical  Society „  180 

TTie  Use  and  Abuse  of  Diatoms  as  Test  Objects „  183 

Measurement  of  the  Amplification  of  Optical  Instruments  ..  „  184 

Support  for  the  Head  in  Drawing  idth  the  Camera  Lucida ..  „  187 

Deceptive  Appearances  produced  by  Reagents     ,,  191 

Preparation  of  Red  Blood-corpuscles „  191 

Apparatus  for  determining  the  Angle  of  the  Optic  Axes  of 

Crystals  with  the  Microscope.    (2  figs.) „  191 

Artificial  Crystals  of  Gold.     (1  fig.) >,  193 

The  Vertical  Illuminator       „  194 

Microscopes  uith  Swinging  Tailpiece,     {l  fig.) No.  3  320 

"  Penetration  "  of  Wide-angled  Objectives ,  322 

Process  for   Measuring   the  Solid   Angles  of  Microscopic 

Crystals „  323 

Method  of  Isolating  the  Connective- Tissue  Bundles  of  the 

Skin „  323 

Process  for  Preparing  the  Embryos  of  Fishes „  325 

Impi-ovement  in  Aerating  Apparatus  of  Sea-water  Aquaria  „  326 
Fwther  Improvements  in  studying  the  Optical  Characters  of 

Minerals „  326 

Improved  Achromatic  Condenser 328 

Seiler's  Mechanical  Microtome.     (1  fig.) „  328 

Size  of  Histological  Preparations         „  329 

'^  Microscopy  "  and '■^  Microscopical"  Societies „  329 

Oil-Immersion  Objectives      ,,  331 

Method  of  Preserving  Infusoria,  4'C „  331 

Mixture  of  Oils  for  Homogeneous-Immersion  Objectives     . .  „  332 

New  Fluids  for  Homogeneous  Immersion „  332 

Standard  Micrometers „  332 

Unit  of  Micrometry      „  332 

Employment  of  Wet  Collodion  for  Microscopic  Sections     . .  No.  4  4G0 

VOL.  II.  C 


XXii  CONTENTS. 

PAGE 

Method  of  Preserving   the    more    delicate   and  perishable 

Animal  Tissues No.  4  461 

Preparation  and  Preservation  of  the  Lower  Organisms      . .  „  462 

Another  Method  of  Preserving  Bacteria,  SfC „  464 

Mounting  Noctiluca  miliaris „  464 

Searching  for  Trichinae         ,,  465 

Method  of  Studying  the  Structure  of  Vegetable  Matter      . .  „  465 

Thin  Stages „  465 

Contrivance  for  Holding  Objects  beneath  the  Stage.     (1  fig.)  „  466 

New  Microtome  {b  figs.)       „  466 

Electrical  Mounting  Table.     (5  figs.) ,,  469 

English  Microscope  for  Students  of  Mineralogy  and  Petro- 
logy 0- fig.)       »  470 

Female  Microscopical  Society       ...  „  472 

Oblique  Illumination „  473 

Limits  of  Accuracy  in  Measurements  with  the  Microscope . .  „  473 

Royal  Society  Conversazione         „  473 

Corrosion  as  a  Histological  Method.     {Plate  XIX.)   ..      ..  No.  5  610 

Staining-fluids       ,,  612 

Br.  Seiler's  Staining  Processes „  613 

Isolation  of  the  Optic  Nerve  Fibres  and  Ganglion  Cells  of  the 

Mammalian  Retina „  614 

Preparation   of  Diatoms  in  situ :  means  of  avoiding  Air- 
bubbles        „  616 

Mechanical  Turntables „  616 

Lmproved  Turntables.     (2  figs.) „  617 

Large  Micro-pihotographs      „  619 

Br.  Sorby  at  Cambridge        .,      „  619 

Unit  of  Micrometry      ,,  620 

Formation   of  the   Paraboloid  as  an  Illuminator  for   the 

Microscope.     (3  figs.)       „  620 

Black-Ground  Illumination „  623 

Rotating  Clips  for  Cheap  Microscopes.    (1  fig.) „  623 

Contrivance  for  holding  Objects  beneath  the  Stage        ..       ..  „  624 

Method  of  preserving  Infusoria,  ^c No.  6  763 

Hcematoxylic  Eosin  and  its  employment  in  Histology  ..      ..  „  764 

Brosicke's  Staining  Method          „  764 

Method  of  examining  Living  Cells  of  Larva  of  Newt ..       ..  „  765 

Vndescribed  Microscopes  {Nachet's).     (Ji  figs.) ,,  765 

Novel  Method  for  Focussing „  767 

Roy  Microtome.     (1  fig.) „  768 

Woodward's  Oblique  Illuminator.     (2  figs.)        „  769 

Improvements  in  Microphotography      ,,  772 

Modern  Applications  of  the  Microscope  to  Geology      ..       ..  „  773 

Adams'  Measuring  Polariscope      „  774 

Homogeneous  Immersion       „  774 

Hamilton  Smith's  "  Universal  Apertometer."     (10  figs.)    . .  „  775 

Measuring  Aperture      „  781 

Woodvjard's  Apertometer.     (1  fig.)     „  781 

Microscopical  Researches  in  High-power  Befinition     ..       ..  „  784 

Soap  as  an  Embedding  Substance          No.  7  940 


CONTKNTS. 


xxin 


Logwood  Staining  Solution 

Modification  of  Farranfs  Medium        

Staining  Fluids  for  Vegetable  Tissues  

Chloride  of  Cadmium  as  a  Fluid  for  Homogeneous  Immer- 
sion   , 

Scientific  Value  of  Microscopic  Preparations       

Counting  of  Blood-corpuscles       

Cheilo-angioscopy 

Value  of  the  Microscope  in  Lata  and  Medicine 

Unit  of  Micrometry 

Comparators  of  Measures  of  Length,     (1  fig.) 

Tolles'  -^  Objective       


Rezner's  Mechanical  Finger.     (4  figs.) 
Apparatus  for  Focussing  Dissecting  Microscopes 
Improved  Mounti)ig  for  Camerce  LucidcB 
Zeiss'  Travelling  Microscope.     (1  fig.) 
Schobl's  Dissecting  Microscope.     (1  fig.) 

Ward's  Improved  Microtome        

Matthew's  Section-cutting  Machine       

Zeiss'  -^  Objective        

Micrometry 


PAGE 

0.  7 

940 

>• 

942 

•' 

942 

i> 

943 

)» 

943 

»> 

944 

)» 

946 

» 

946 

)) 

947 

)> 

947 

)i 

951 

951 

» 

954 

„ 

954 

„ 

955 

956 

•> 

957 

)• 

957 

)> 

958 

958 

Bibliography  of  current  researches  relating  to  Invertebrata, 
Cryptogamia,   Microscopy,   &c.,  including   Embryology    and 

Histology  GENERALLY 97,  196,  210*,  335,  474,  625,  787,  959 

Proceedings  of  the  Society — 

December  11,  1878         No.  1  105 

January  8,  1879      „  109 

February  12  (Annual  Meeting) No.  2  211 

Report  of  the  Council  presented  to  the  Annual  Meeting      .,         „  216 

Treasurer's  Accounts  for  1878 „  218 

March  12         „  219 

April  9  (Ordinary  and  Special  General  Meeting)     No.  3  344 

May  14 No.  4  488 

May  21  (Scientific  Evening)         No.  5  651 

June  11 „  645 

June  18  (Ordinary  Wednesday  Evening  Meeting  in  the  Library)     ,,  650 

Octobers No.  7  982 

November  12 „  987 


Obitcary 
Index 


No.  3       333 
991 


c2 


XXIV 


LIST  OF  PLATES. 


TO  FACE 
PAGE 


PLATE 

I. — CEcistes  umhella No.  1         1 

II. — ConocMlus  volvox         

III. — Limits  of  Microscopic  Vision 

IV.^— New  Sense-organs  iu  Insects ,• 


\.—Dactylocalyx  Stutchhuryi{Sollas)      No.  2     122 


VI.-        „  „  ..     .. 

VII. — Spicules  of  Dactylocahjx  pumiceus 
VIII.' — Spicules  of  Dactylocalyx  pumiceus  and  D.  Stutchburyi 


1^ 
122 
122 


IX. — Teg eocr anus  latus        No.  3  225 

,        X. — Nothrus  theleproctus,  Tegeocranus  elongatus     „  225 

XI. —  Tegeocranus  coriaceus,  T.  lahyrinthicus,  and  Sciitovertex  sculptus       „  225 
XII. — Diagrams  exhibiting  the  Path  of  a  Kay  through  ToUes'  ^ 

Immersion  Objective „  269 

'     iDevelopment  and  Retrogression  of  the  Fat-Cell       ,.      ..  No.  4  353 

XV. — Hcteropora  pelUculata,  Operculum  of  Myriozoum  suhgracile, 
Operculum  of  Cellepora,  Cellepora  sp.,  Hcteropora  cervicornis 

D'Orb.     ..      ,.    ■ „  390 

XVI. — Halosphcera,  a  New  Genus  of  Unicellular  Algaj „  458 

XVII. — Alectona  Millari  n.  sp No.  5  493 

XVIIa. — Bhaphidotheca  affinis  n.  sp.,  Aphrosina  informis  nov.  gen.  et  sp.       „  500 

XVIII. — Notommata  Wcrneckii,  and  its  Galls  on  Vaucheria  terrestris  ..        „  530 

XIX. — Corrosion  as  a  Hiatological  Method        „  612 

XX. — Cothurnia  corrugata No.  6  653 

XXI. — New  Species  of  Diatomaceae  from  the  Caspian  Sea    . .      . .       „  677 

^^jj-~JMorphology  of  Vegetable  Tissues        No.  7  801 

^-^-y' \Anatom.y  oi  Leptodora  hyalina       „  825 

XXVI. — Monobia  confluens       „  901 


(      XXV      ) 


LIST  OF  WOODCUTS. 


FAGB 

Hofmann's  Camera  Liicida  (4  figs.)        No.  1       21 

Swift's  Camera  Lucida ..  „          23 

Eussell's  Camera  Lucida  (2  figs.) „          25 

Diagram  of  Stephenson's  Catoptric  Immersion  Illuminator        ....  „          36 

Prazmowski's  Heliostat „          4:4 

Weber  Slide        „          56 

Measure  for  Covering-glass  (8  figs.)        ,,          65 

Improvements  in  Object-glasses      »          76 

Figures  illustrating  Mr.  W.  J.  Sollas'  paper  on  Dactylocalyx  pumiceus 

(Stntchbury)  (4  figs.) No.  2  124-33 

A  New  Rotifer — Anurcca  longispina „         158 

Sponge  Spicules         „        178 

Lasaulx'  Apparatus  for  determining  the  Angle  of  the  Optic  Axes  of 

Crystals  with  the  Microscope  (2  figs.)      „     192-3 

Artificial  Crystals  of  Gold        „         194 

Swinging  Tailpiece  for  Microscopes        No.  3    320 

Seller's  Mechanical  Microtome        „        329 

Hoggan's  Histological  Ring No.  4    357 

Pt'cfa/wft  (Huilson)  and  i^i?^ar<Ara  (Schmarda)  (2  figs.)        „         386 

Tolles'  Illuminating  Traverse  Lens         „        388 

Phin's  Contrivance  for  holding  Objects  beneath  the  Stage       ..      ..  „        466 

Fletcher's  Microtome  (5  figs.) „     407-8 

Rogers'  Electrical  Mounting  Table  (3  figs.) „  4G9-70 

English    Microscope    for    Students  of  Mineralogy  and   Petrology 

(Rutley's)      „         471 

Diagrams  illustrating  Dr.  Fripp's  paper  on  the  Theory  of  Illumi- 
nating Apparatus  (9  figs.)         No.  5  510-24 

Snare  of  Epcira  basilica       „         560 

Algse  from  Lake  Nyassa  (3  figs.) „        608 

Rolfe's  Improved  Turntables  (2  figs.) „         618 

Formation  of  the  Paraboloid  as  an  Illuminator  for  the  Microscope 

(3  figs.)          „     620-1 

Rotating  Clips  for  Cheap  Microscopes „        624 

Figures  illustrating  Dr.  Ord's  paper  on  Brownian  Movements  (2  figs.)  No.  6     659 
"Microscope  nouveau  grand  modele  renverse'  avcc  miroir  argente " 

(Nachet)        „        766 

Portable  Demonstration  Microscope  (Nachet)  (2  figs.)        „        767 

Roy  Microtome „        769 

Woodward's  Oblique  Illuminator  (2  figs.)      „     770-2 


XXVI 


LIST   OF   WOODCUTS. 


PAGE 

Hamilton  Smith's  "  Universal  Apertometer  "  (10  figs.)       ..      ..        No.  6  775-9 

Woodward's  Apertometer „        782 

Diagram  illustrating  Professor  Abbe's  Paper  on  Methods  for  Im- 
proving Spherical  Correction     No.  7    817 

JEucampia  striata  (4  figs.) 835 

Mayall's  Immersion  Stage  Illimiinator 

Rogers'  Comparator  for  Measures  of  Length 

Rezner's  Mechanical  Finger  (4  figs.)      

Zeiss'  Travelling  Microscope 

Schobl's  Dissecting  Microscope       


837 
948 
951-3 
955 
956 


(     xxvii    ) 


MEMORANDUM  AS  TO  THE  BIBLIOGRAPHY. 

The  primary  object  of  the  Bibliography  is  to  note  all  original 
articles  and  papers.  Whilst  not  impossible  to  include  everything 
(within  the  scope  of  the  Bibliography)  contained  in  the  Journals, 
Transactions,  &c.,  in  the  list  appended,  it  would  obviously  not  be 
beneficial  to  do  so,  as  the  original  papers  would  then  be  lost  in  a  mass 
of  less  important  titles. 

There  are  therefore  omitted  (subject  to  special  exceptions) : 
(1)  Abstracts  of  papers  appearing  in  other  Journals,  (2)  Cor- 
respondence, (3)  Discussions  at  Meetings  of  Societies,  (4)  Notes, 
(5)  Reviews  of  Books,  &c.,  (6)  Articles  copied  into  another 
publication  in  the  same  language  or  translated  from  the  English 
language. 

The  Bibliography  is  classified  as  follows  : — 

ZOOLOGY. 

A.  General  (including  Embryology  and  Histology  of  the  Vertebrata). 

B.  Invertebrata. 

MOLLUSCA. 
MoLLUSCOIDA. 

Aethropoda. 

(o)  Insecta  (omitting   lists  and  descriptions  of  new  species, 
local  fauna,  &c.). 

(/3)  Myeiapoda. 

(7)  Aeachnida. 

(5)  Crustacea. 
Vermes. 

echinodeemata. 
ccelenterata. 
poeifera. 
Peotozoa. 

BOTANY. 

A.  General  (including    Embryology  and  Histology  of  the  Phanero- 


B.  Cryptogamia. 

Cryptogamia  Vascularia. 

Mdscine^. 
Charace^. 
Fungi. 

LiCHENES. 
ALGiB. 

MICROSCOPY,  &c. 

Methods. 
Instrumental,  &c. 


(     xxviii     ) 

List  of  the  Jouenals,  Teansactions,  etc., 

the  Contents  of  which  will  he  noted  in  the  Bibliogra'phy 
as  j^uhlished. 

UNITED  KINGDOM. 
England. 
Annals  and  Magazine  of  Natural  History. 
Entomologist. 

Entomologist's  Monthly  Magazine. 
Geological  Magazine. 
Grevillea. 

Hardwicke's  Science-Gossip. 
Journal  of  Anatomy  and  Physiology  (Humphry). 
Journal  of  Botany. 
Journal  of  Conchology. 
Journal  of  Physiology  (Foster). 
Midland  Naturalist. 
Monthly  Journal  of  Science. 
Naturalist. 
Nature. 

Popular  Science  Review. 
Quarterly  Journal  of  Microscopical  Science. 
Zoologist. 

London.  British  Association  for  the  Advancement  of  Science— Eeport. 

Entomological  Society— Transactions. 

Geological  Society— Quarterly  Journal. 

linnean  Society— Journal :  (1)  Botauy  ;  (2)  Zoology. 
M  )«        Transactions:  (1)  Botany;  (2)  Zoology. 

PalseontograpMcal  Society-(Publications). 

Quekett  Microscopical  Club— Journal. 

Ray  Society— (Publications). 

Royal  Microscopical  Society— Journal. 

Royal  Society— (1)  Proceedings.     (2)  Philosophical  Transactions. 

Royal  Institution— Proceedings. 

Zoological  Society— (1)  Proceedings.    (2)  Transactions. 
Bristol.  Naturalists'  Society— Proceedings. 
Liverpool.  Literary  and  Philosophical  Society— Proceedings. 
Manchester.  Literary  and  Philosophical  Society— Memoirs. 
Newcastle-upon-Tyne.  Natural  History  Society  of  Northumberland,  Durham, 

and  Newcastle-upon-Tyne— Transactions. 
Norwich.  Norfolk  and  Norwich  Naturalists'  Society— Transactions. 

Scotland. 

Scottish  Naturalist. 

Edinburgh.  Royal  Society— (1)  Proceedings.     (2)  Transactions. 

„  Botanical  Society— Transactions  and  Proceedings. 

„  Geological  Society— Transactions. 

Glasgow.  Society  of  Natural  History— Proceedings. 


(     xxix     ) 

Ireland. 
Dublin.  EcJ^al  Irish  Acadeiny-(l)  Proceedings.    (2)  Transactions. 
„        Royal  Geological  Society  of  Ireland— Journal. 


COLONIES. 

India. 
Calcutta.  Asiatic  Society  of  Bengal— (1)  Journal.    (2)  Proceedings. 
,,  Geological  Survey  of  India— (1)  Kecords.    (2)  Memoirs. 

Australasia. 

New  South  Wales.  Linnean  Society— Proceedings. 

„  ,,  Royal  Society— Journal  and  Proceedings. 

South  Australia.  Philosophical  Society  of  Adelaide— Transactions  and  Pro- 
ceedings. 
Victoria.  Royal  Society— Transactions  and  Proceedings. 

„         Microscopical  Society— Quarterly  Journal. 
Tasiiajjia.  Royal  Society— Papers  and  Proceedings. 
New  Zealajo)  Institute.  Transactions  and  Proceedings. 

Canada. 

Canadian.  Entomologist. 

Canadian  Naturalist  and  Quarterly  Journal  of  Science. 

Halufax.  Nova  Scotian  Institute  of  Natural  Science— Proceedings  and  Trans- 
actions. 

Toronto.  Canadian  Institute— The  Canadian  Journal :  Proceedings  of  the 
Institute. 


UNITED  STATES. 

American  Journal  of  Microscopy  and  Popular  Science. 
American  Journal  of  Science  and  Arts. 
American  Naturalist- 

Boston.  American  Academy  of  Aits  and  Sciences— (1)  Proceedings.  (2)  Memoirs. 

„        Society  of  Natural  History— (1)  Proceedings.     (2)  Memoirs. 
Cambridge.  Museum  of  Comparative  Zoology  at  Harvard  College— (1)  Bulletin. 
(2)  Memoirs. 
,,  Entomological  Club— Psyche. 

Cincinnati.  Society  of  Natural  History— Journal. 
Connecticut.  Academy  of  Arts  and  Sciences— Transactions. 
New  York.  Academy  of  Sciences— Annals. 

Philadelphia.  Academy  of  Natural  Sciences— (1)  Proceedings.    (2)  Jomnal. 
„  American  Entomological  Society— Transactions. 

,,  American  Philosophical  Society— Proceedings. 

Salem.  American  Association  for  the  Advancement  of  Science— Proceedings. 
St.  Louis.  Academy  of  Science— Transactions. 
Washington.  National  Academy  of  Sciences— Memoirs. 

,,  United  States  Geological  and  Geographical  Survey  of  the  Terri- 

tories—Bulletins. 
„  Smithsonian  Institution— (1)  Miscellaneous  Collections.  (2)  Con- 

tributions to  Knowledge. 
,,  United  States  National  Museum— (1)  Bulletin.   (2)  Proceedings. 


(        XXX       ) 


GERMANY. 


ArcMv  fiir  Anatomie  und  Entwickelungsgeschiclite  (His). 

„  Mikroskopische  Anatomie. 

„  pathologische  Anatomie  und  Physiologie  und  fiir  klinische  Medicin 

(Viichow). 

„  Naturgeschichte. 

,,  Physiologie  (Du  Bois-Reymond). 

,,  die  gesammte  Physiologie  des  Menschen  und  der  Thiere  (Pfluger). 

Botanische  Abhandlungen  aus  dem  Gebiet  der  Morphologic  und  Physiologie 

(Hanstein). 
Botanische  Zeitung. 
Deutsche  Entomologische  Zeitschrift. 
Entomologische  Nachrichten. 
Flora. 
Hedwigia. 

Jahrbiicher  fiir  Wissenschaftliche  Botanik. 
Jenaische  Zeitschrift  fiir  Naturwissenschaft. 
Kosmos. 
Linnsea. 

Malakozoologische  Blatter. 
Morphologisches  Jahrbuch. 
Naturforscher. 

Neues  Jahrbuch  fur  Mineralogie,  Geologie  und  Palaontologie. 
Palgeontographica- 
Stettiner  Entomologische  Zeitung. 
Zeitschrift  fiir  Mikroskopie. 

n  die  gesammten  Naturwissenschaften. 

I,  Wissenschaftliche  Zoologie. 

Zoologischer  Anzeiger. 

Deutsche  Naturforscher  und  Aerzte— Berichte  iiber  die  Versammlungen. 
Berlin.    K.  Preussische  Akademie  der  Wissenschaften— (1)   Monatsberichte. 
(2)  Abhandlungen. 
,,         Deutsche  Geologische  Gesellschaft— Zeitschrift, 
,,         Gesellschaft  Naturforschender  Freunde— Sitzungsberichte. 
,,         Botanischer  Verein  der  Provinz  Brandenburg— Verhandlungen. 
Bonn.  Naturhistorischer  Verein  der  Preussischen  Kheinlande  und  Westfalens— 
Verhandlungen. 
„       Niederrheinische  Gesellschaft  fiir   Natur-  und  Heilkunde  —  Sitzungs- 
berichte. 
Bkemen.  Naturwissenschaftlicher  Verein— Abhandlungen. 
Breslau.  Schlesische  Gesellschaft  fiir  Vaterlandische  Cultur— Jahresberichte. 
Danzig.  Naturforschende  Gesellschaft— Schriften. 

Dresden.  K.  Leopoldinisch-Carolinische  Deutsche  Akademie  der  Naturforscher— 
(1)  Loopoldina.     (2)  Verhandlungen  (Nova  Acta). 
„         Naturwissenschaftliche  Gesellschaft  "  Isis  "—Sitzungsberichte. 
Erlanqen.  Physikalisch-medicinische  Societat— Sitzungsberichte. 
Frankfurt  a.  M.  Senckenbergische  Naturforschende  Gesellschaft— (1)  Berichte. 
(2)  Abhandlungen. 
„  ,,  Deutsche  Malakozoologische  Gesellschaft  —  (1)  Jahrbiicher. 

(2)  Nachrichtsblatter. 
GiEssiN.  Oberhessische  Gesellschaft  fiir  Natur-  und  Heilkunde— Berichte. 


(     xxxi     ) 

GoTTiNGEN.  K.  Gesellschaft  der  Wissenschaften  und  Georg-Augusts-Universitat 
—(1)  Nachricliten.    (2)  Abhandlungen. 

„  Botanisches  Laboratorium  der  Universitat— Untersucbungen. 

Geeepswald.  Naturwissenschaftlicher  Verein  von  Neu-Vorpommern  und  Riigen— 

Mittbeilungen. 
Halle.  Naturforschende  Gesellschaft— Abbandlungen. 

Hamburg.  Verein  ftir  Naturwissenschaftliche  Unterhaltung— Verhandluno-en. 
Heidelbcrg.  Naturhistorisch-mediciniscber  Verein — Verbandluno-en. 

„  Pbysiologisches  Institut  der  Universitat— Untersucbungen. 

Jena.  Medicinisch  -  Naturwissenschaftliche  Gesellschaft— (1)  Sitzuno-sberichte 

(2)  Denkscbriften.  ° 

Konigsberg.  K.  Physikalisch-okonomische  Gesellschaft— Scbriften. 
Leipzig.  K.  Sachsische  Gesellschaft  der  Wissenschaften— Abbandluno-en. 

,,         Naturforschende  Gesellschaft— Sitzungsbericbte. 
MECKLE>fBURG.  Verein  der  Freunde  der  Naturgeschichte— Arcbiv. 
Munich.  K.  Bayerische  Akademie  der  Wissenschaften— (1)  Sitzungsberichte. 
(2)  Abbandlungen. 
,,         Entomologischer  Verein— Mittbeilungen. 
Stuttgart.  Verein  fiir  vaterlandische  Naturkunde— Jabrcsbefte. 
WijEZBURG.  Zoologisch-zootomisches  Institut— Arbeiten. 

,,  Physikalisch-medicinische  Gesellschaft— Verbandlungen  (including 

S  itzungsbericbt  e) . 
„  Botanisches  Institut— Arbeiten. 


AUSTRIA-HUNGARY. 

Magyar  Novenytani  Lapok. 
Oesterreichische  Botanische  Zeitschrift. 
Termeszetrajzi  Fuzetek  (Naturhistorische  Hefte). 

BbUnn.  Naturforschender  Verein— Verbandlungen. 

Budapest.  A  Magyar  Tud6s  Tarsasag— Evkonyvei. 

Gratz.  Naturwissenschaftlicher  Verein  ftir  Steiermark— Mittbeilungen. 

Hermannstadt.   Siebenbiirgischer  .Verein  fiir  die  Naturwissenschaften— Ver- 
bandlungen. 

Innsbruck.  Naturwissenschaftlich-Medicinischer  Verein— Berichte. 

Prague.   K.  Bdhmische  Gesellschaft  der  Wissenschaften— (I)  Sitzungsberichte. 
(2)  Abbandlungen. 

Trieste.  Societa  Adriatica  di  Scienze  Naturali— BoUettino. 

Vienna.  K.  Akademie   der  Wissenschaften— (1)  Sitzungsberichte  (1st  and  3rd 
sections).     (2)  Denkscbriften. 
,,         K.  K.  Zoologisch-botanische  Gesellschaft— Verbandlungen. 
„         K.  K.  Geologische  Reichsanstalt— (1)  Abhandlungen.    (2)  Jabrbucb. 

(3)  Verbandlungen. 
„         Embryologisches  Institut  der  K.  K.  Universitat— Mittbeilungen. 
,,         Zoologisches  Institut  der  Universitat  Wien  und  Zoologische  Station  in 
Triest— Arbeiten. 


(     xxxii     ) 


HOLLAND. 


Niederlandisches  ArcMv  fiir  Zoologie. 

Tijdsclu-ift  voor  Entomologie. 

Amsterdam.  K.  Akademie  vanWetenschappen— (1)  Verslagen  en  Mededeelingeu. 

{2)  Verhaudeliugen. 
Haablem.  HoUandsche  Maatschappij  der  Wetenschappen  (Societe  Hollandaise 
des  Sciences)— (1)  Archives  Ne'erlandai.ses  des  Sciences' Exactes  et 
Natui'elles.     (2)  Natuurkuudige  Verhandelingen. 
Leiden.  Nederlandsche  Dierkundige  Vereeniging— Tijdsclirift. 
NiJMEGEN.  Nederlandsche  Botanische  Vereeniging— Verslagen   en  Mededeel- 

ingen.    (Nederlandsch  Kniidkundig  Arehicf.) 
Uteecht.  Provinciaal  TJtrechtsch  Genootschap  van  KunstenenWetenschappen— 
Natuurkundige  Verhandelingen. 
„  Physiologiscli  Laboratorium  der  TJtrechtsche  Hoogeschool— Onder- 

zoekingen. 
Batavia.  Natuurkundig  Tijdschrift  voor  Nederlandsch  Indie. 

„  Bataviaasch  Genootschap  van  Kunsten  en  Wetenschappen— (1)  Notu- 

len  van  de  Algemeene  en  Bestuurs-Vergaderingen.    (2)  Tijdschrift 
voor  Indische  Taal-  Land-  en  Volkenkunde.    (3)  Verhandelingen. 


DENMARK. 

Botanisk  Tidsskrift.    (Journal  de  Botanique.) 

Naturhistorisk  Tidsskrift. 

Copenhagen.  K.  Danske  Videnskabemes  Selskab— (1)  Oversigt.    (2)  Skrifter. 


SWEDEN  and  NORWAY. 

ArcMv  for  Mathematik  og  Naturvidenskab. 

Botaniska  Notiser. 

Nyt  Magazin  for  Naturvidenskaberne. 

Lund.  Universitet— Ars-skrift  (Acta). 

Stockholm.  K.  Svenska  Vetenskaps-Akademien— (1)  Ofversigt  af  .  .  .  Furhand- 

liugar.     (2)  Handliiigar. 
Upsala.  K.  Societas  Scientiarum  TJpsaliensis— Nova  Acta. 


RUSSIA. 

Helsingfors.  Societas  pro  Fauna  et  Flora  Fennica— (1)  Meddelanden.  (2)  Acta. 
Moscow.  Societe  Imperiale  des  Naturalistes— (1)   Bulletin.      (2)   Nouvcaus 

Me'moires. 
Odessa.  Neurussische  Naturforschende  Gesellschaft— Dcukscliriften. 
St.  BETERSBtiKG.  Academie  Imperiale  des  Sciences— (1)  Bulletin.  (2)  Me'moires. 

„  Societe  Imperiale  des  Naturalistes— Bulletin. 

„  Societas  Entomologica  Eossica— Horaj. 

„  Russische  Entomologisclie  Gesellschaft— Arbeiten. 


SWITZERLAND. 

Archives  des  Sciences  Physiques  et  Naturelles. 
Baseu  Naturforschende  Gesellschaft— Vcrhandlungen. 

,.      Schweizerische  Palaeontographische  Gesellschaft-Abhandluugcn. 


(     xxxiii     ) 

Bern.  Naturforschende  Gesellschaft— Mittheiluugeu. 

Chub.  Naturforschende  Gesellschaft  Graubundens— Jahresbcrichtc. 

Geneva.  Societe  de  Physique  et  d'Histoire  Naturelle— Memoires. 

,,         Institut  National  Genevois— (1)  Bulletin.     (2)  Memoires. 
Lattsanne.  Societe  Vaudoise  des  Sciences  Naturelles— Bulletin. 
ScHAFFHAUSEN.  Schweizerischo  Entomologische  Gesellschaft— IMittheilungen. 
ZURICH.   Allgemeine  Schweizerische  Gesellschaft  fiir  die  gesammten  Natur- 

wissenschaften  (Societe  Helvetique  des  Sciences  Naturelles)— Neue 

Deulischriften  (Nouveaux  Me'moires). 
„       Naturforschende  Gesellschaft— (1)  Vierteljahrsschrift.    (2)  Abhand- 

lungen. 


FRANCE. 

Adansonia, 

Annales  des  Sciences  Naturelles— Botanique. 

,,  ,1  )i  Zoologie. 

Archives  de  Zoologie  Experimentale  et  Generale  (Lacaze-Duthiers). 
Ai-chives  de  Physiologic  normals  et  Pathologiqne  (Brown-Sequard). 
Erehissonia. 

Bulletin  Scientifique  du  Departement  du  Nord  et  des  Pays  voisins- 
Journal  de  I'Anatomie  et  de  la  Physiologie  (Robin). 
„  Conchyliologie. 

„         Micrographie. 
Bevue  Bryologique. 

,•      Internationale  des  Sciences. 

,,      et  Magazin  de  Zoologie  pure  et^appliquee. 

„      Mycologique. 

,,      des  Sciences  Naturelles. 

„      Scientifique. 
AiHENS.  Societe  Linneenne  du  Nord  de  la  France  —  (1)    Bulletin    meusuel. 

(2)  Me'moires. 
BoEDEAUx.  Societe  des  Sciences  Physiques  et  Naturelles— Memoires. 

,,  Societe  Linneenne— Actes. 

Caen.  Societe  Linneenne  de  Normandie— (1)  Bulletin.     (2)  Me'moires. 
Cheebourg.  Societe  Nationals  des  Sciences  Naturelles— Me'moires. 
Lille.  Societe  des  Sciences— Travaux  et  Me'moires. 
Lyons.  Academie  des  Sciences,  Belles-Lettres  et  Arts— Me'moires. 

„       Societe  Linneenne— Annales. 
Marseille.  Academic  des  Sciences,  Belles-Lettres  et  Arts— Me'moires. 
MoNTPELLiER.  Academic  des  Sciences  et  Lettres— Me'moires. 
Paris.  Academie  des  Sciences- (1)  Comptes  Rendus.  (2)  Me'moires.  (3)  Me'moires 
presentt'S  par  divers  Savants. 

, ,      Association  Fran5aise  pour  1' Avancement  des  Sciences-  Comptes  Rendus. 

„       Laboratoire  d'Histologie  du  College  de  France— Travaux. 

„       Societe  de  Biologie-(l)  Comptes  Rendus  des  Seances.     (2)  Me'moires. 

„       Societe  Botanique  de  France— Bulletin. 

„       Societe  Entomologique  de  France— Annales. 

„       Societe  Geologique  de  France-(l)  Bulletin.     (2)  Me'moires. 

,,       Societe  Philomathique— Bulletin. 

,,       Societe  Linneenne  de  Paris- Bulletin  mensuel. 


(     xxxiv     ) 

Paris.  Museum  d'Histoire  Naturelle— Nouvelles  Archives. 

,,       Societe  Zoologique  de  France— Bulletin. 
Toulouse.  Academie  des  Sciences,  Inscriptions  at  Belles-Lettres— Me'moires. 
„  Societe  d'Histoire  Naturelle— Bulletin. 


BELGIUM. 

Brussels.  Academie  Eoyale  des  Sciences,  des  Lettres  et  des  Beaux  Arts  de 

Belgique— (1)  Bulletins.     (2)  Me'moires.    (3)  Me'moires  Couronnes 

et  Memoires  des  Savants  Strangers,  4to.     (4)  Me'moires  Couronue's 

et  autres  Me'moires,  8vo. 

,,         Societe  Royale  de  Botanique  de  Belgique— Bulletin. 

,,         Societe  Beige  de  Microscopie— Annales  :  (1)  Memoires;  (2)  Bulletin. 

„         Societe  Entomologique  de  Belgique  —  Annales  (iucluding  Comptes 

Eendus). 
„         Societe    Malacologique    de    Belgique  — Annales  (including  Proces- 
Verbaus). 
Liege.  Societe  Geologique  de  Belgique— Annales  :  (1)  Me'moires ;  (2)  Bulletin. 


ITALY. 

Nuovo  Giornale  Botanico  Italiano. 

Bologna.  Accademia  di  Scienze  dell'  Istituto— (1)  Memorie.     (2)  Rendiconti. 
Florence.  Societa  Entomologica  Italiana— Bullettini. 
„  Societa  Malacologica  Italiana— Bullettini. 

Genoa.  Museo  Civico  di  Storia  Naturale— Annali. 
Milan.  Societa  Crittogamologica  Italiana— Atti. 

„       Societa  Italiana  di  Scienze  Naturali— Atti. 

„       R.  Istituto  Lombardo  di  Scienze  e  Lettere— (1)  Eendiconti.  (2)  Memorie. 
MoDENA.  Societa  dei  Naturalisti— Annuario. 

Naples.  K.  Accademia  delle  Scienze  Fisiche  e  Matematiche— (1)  Atti.  (2)  Ken- 
dicouti. 

,,        Zoologische  Station— (1)  Mittheilungen.     (2)  Fauna  und  Flora  des 
Golfes  von  Neapel. 
Padua,  Societa  Veneto-Trentina  di  Scienze  Naturali— Atti. 
Pa  VIA.  Lavoratorio  di  Botanico— Archivio  triennale. 
Pisa.  Societa  Toscana  di  Scienze  Naturali— Atti. 
KoME.  R.  Accademia  dei  Lincei— Atti :  (1)  Transunti ;  (2)  Memorie. 

„       R.  Comitate  Geologico  d' Italia— BoUettini. 
Turin.  R.  Accademia  delle  Scienze— (1)  Atti.    (2)  Memorie. 
Venice.  R.  Istituto  Veneto  di  Scienze,  Lettere  ed  Arti— (1)  Atti.   (2)  Memorie. 


SPAIN. 
Madrid.  Sociedad  Espanola  de  Historia  Natural— Anales. 


PORTUGAL. 

Lisbon.  Academia  R.  das  Sciencias— (1)  Jornal  de  Sciencias   Mathematicas, 
Physicas  e  Naturaes.     (2)  Memorias. 


THE 


(Founded  in  1839.     Incorporated  by  Eoyal  Charter  in  1866.) 


The  Society  was  established  for  the  commimication  and  discussion 
of  observations  and  discoveries  (1)  tending  to  improvements  in  the  con- 
struction and  mode  of  application  of  the  Microscope,  or  (2)  relating  to 
Biological  or  other  subjects  of  Microscopical  Eesearch. 

It  consists  of  Ordinary,  Honorary,  and  Ex-officio  Fellows. 

Ordinary  Fellows  are  elected  on  a  Certificate  of  Eecommendatiou 
signed  by  three  Fellows,  stating  the  names,  residence,  description,  &c., 
of  the  Candidate,  of  whom  one  of  the  proposers  must  have  personal 
knowledge.  The  Certificate  is  read  at  a  Monthly  Meeting,  and  the 
Candidate  balloted  for  at  the  succeeding  Meeting. 

The  Annual  Subscription  is  £2  2s.,  payable  in  advance  on  election, 
and  subsequently  on  1st  January  annually,  with  an  Entrance  Fee  of  £2  2s. 
Future  payments  of  the  former  may  be  comi^ounded  for  at  any  time  for 
£31  10s.  Fellows  elected  in  October,  November,  or  December,  are  not 
called  upon  for  a  subscription  during  the  succeeding  year,  and  Fellows 
absent  from  the  United  Kingdom  for  a  year,  or  permanently  residing 
abroad,  are  exempt  from  one-half  the  subscription  dui'ing  absence. 

Honorary  Fellows  (limited  to  50),  consisting  of  persons  eminent 
in  Biological  or  Microscopical  Science,  are  elected  on  the  recommendation 
of  three  Fellows  and  the  approval  of  the  Council. 

Ex-oflacio  Fellows  (limited  to  100)  consist  of  the  Presidents  for 
the  time  being  of  such  Societies  at  home  and  abroad  as  the  Council  may 
recommend  and  a  Monthly  Meeting  approve.  They  are  entitled  to  receive 
the  Society's  Publications,  and  to  exercise  all  other  privileges  of  Fellows, 
except  voting,  but  are  not  required  to  pay  any  Entrance  Fee  or  Annual 
Subscription. 

The  Council,  by  whom  the  affairs  of  the  Society  are  managed,  is 
elected  annually,  and  is  composed  of  the  President,  four  Vice-Presidents, 
Treasurer,  two  Secretaries,  and  twelve  other  Fellows. 

The  Meetings  are  held  on  the  second  Wednesday  in  each  month, 
from  October  to  June,  in  the  Society's  Library  at  King's  College,  Strand, 
W.C.  (commencing  at  8  p.m.).  Visitors  are  admitted  by  the  introduction  of 
Fellows. 

In  each  Session  two  additional  evenings  ("  Scientific  Evenings  ")  are 
devoted  to  the  exhibition  of  Apparatus  and  Objects  of  novelty  or  interest 
relating  to  the  Microscope  or  the  subjects  of  Microscopical  Eesearch. 

The  Journal,  containing  the  Transactions  and  Proceedings  of  the 
Society,  with  a  Record  of  Current  Researches  relating  to  Invertebrata, 
Cryptogamia,  Microscopy,  &c.,  is  published  bi-monthly,  and  is  forwarded 
gratis  to  all  Ordinary  and  Ex-officio  Fellows  residing  in  countries  within 
the  Postal  Union. 

The  Library,  with  the  Instruments,  Apparatus,  and  Cabinet  of 
Objects,  is  open  for  the  use  of  Fellows  on  Mondays,  Tuesdays,  Thursdays, 
and  Fridays,  from  11  a.m.  to  4  p.m.,  and  on  Wednesdays  from  7  to  10  p.m. 
It  is  closed  during  August. 

Forms  of  proposal  for  Fellowship,  and  any  further  information,  vmy  he  obtained  by 
application  to  the  Secretaries,  or  Assistant-Secretary,  at  the  Library  of  the  Society, 
King's  Colkge,  Strand,  W.C. 


*   * 


Omissions  having  occasionally  occurred  in  the  Obituary  Notices 
at  the  Anniversary  Meetings  of  the  Society,  it  is  requested  that  any 
information  loith  respect  to  Deceased  Fellows,  as  also  notice  of  changes 
of  residence,  he  addressed  to  the  Assistant  Secretary,  at  the  Society's 
Library,  King's  College,  Strand,  W.C, 


HIS   ROYAL   HIGHNESS 

ALBERT    EDWARD,  PRINCE   OF  WALES, 

E.G.,  G.C.B.,  F.R.S.,  &c. 


!ast-|lrcsiben;ts. 


Elected. 

Richard  Owen,  C.B.,  M.D.,  D.C.L.,  LL.D.,  F.R.S 1840-1 

John  Lindley,  Pli.D.,  F.R.S 1842-3 

Thomas  Bell,  F.R.S 1844-5 

James  Scott  Bowebbank,  LL.D.,  F.R.S 184G-7 

George  Busk,  F.R.S 1848-9 

Arthur  Farre,  M.D.,  F.R.S 1850-1 

George  Jackson,  M.R.C.S 1852-3 

William  Benjamin  Carpenter,  C.B.,M.D.,  LL.D.,  F.R.S.       1854-5 

George  Shadbolt 1856-7 

Edwin  Lankester,  M.D.,  LL.D.,  F.R.S 1858-9 

John  Thomas  Quekett,  F.R.S 1860 

Robert  James  Faurants,  F.R.C.S 1861-2 

Charles  Brooke,  M.A.,  F.R.S 1863-4 

James  Glaisher,  F.R  S 1865-6-7-8 

Rev.  Joseph  Bancroft  Reade,  M.A.,  F  R.S 1869-70 

William  Kitchen  Parker,  F.R.S 1871-2 

Charles  Brooke,  M.A.,  F.R.S 1873-4 

Henry  Clifton  Sorby,  LL.D.,  F.R.S 1875-6-7 

Henry  James  Slack,  F.G.S 1878 


VOL.    II. 


COUNCIL. 

Elected  12th  Febeuary,  1879. 


Lionel  S.  Beale,  Esq.,  M.B,,  F.R.S. 

0ice-^rcsibcnis. 

Robert  Braithwaite,  Esq.,  M.D.,  M.R.C.S.,  F.L.S. 

Charles  T.  Hudson,  Esq..  M.A..,  LL.D. 

Henry  J.  Slack,  Esq.,  F.G.S. 

Henry  C.  Sorby,  Esq.,  LL.D.,  F.R.S.,  P.G.S. 

treasurer. 

John  Ware  Stephenson,  Esq.,  F.R.A.S. 

Charles  Stewart,  Esq.,  M.R.C.S.,  F.L.S. 
Frank  Crisp,  Esq.,  LL.B.,  B.A.,  F.L.S. 

^Aijelbij  otijcr  gtcmljers  of  Coundl. 

John  Badcock,  Esq. 

William  A.  Bevington,  Esq. 

Charles  James  Fox,  Esq. 

James  Glaisher,  Esq.,  F.R.S. 

William  J.  Gray,  Esq.,  M.D, 

A.  DE  SouzA  Guimaraens,  Esq. 

John  E.  Ingpen,  Esq. 

Emanuel  W.  Jones,  Esq.,  F.R.A.S. 

William  T.  Loy,  Esq. 

John  Matthews,  Esq.,  M.D. 

John  Millar,  Esq.,  L.R.C.P.  Ediu.,  F.L.S. 

Thomas  Palmer,  Esq.,  B.Sc. 


ORDINARY   FELLOWS. 


*  Fellows  who  have  compounded  for  tlieir  Annual  Suhscnptions. 


Abbott,  Francis,  F.R.A.S. 

Hie  Observatory,  Hohart  Town,  Tasmania. 
*Abercrombie,  John,  M.D.  (Cantab.),  F.R.C.P. 

13,  Suffolk-square,  Cheltenham. 
Abraham,  Phineas. 

Eoyal  College  of  Surgeons  in  Ireland,   Museum  Depart- 
ment, Dublin. 
Ackland,  William,  L.S.A. 

416,  Strand,  W.C. 
Alabone,  Edwin  W.,  M.D.,  M.E.C.S. 

Lynton  House,  Mildmay-road,  N. 
Alexander,  Lieut.-General  Sir  James,  R.A.,  Kt.,  C.B. 

35,  Bedford-place,  Bussell-sqiiare,  W.C 
Allbon,  William. 

525,  New  Oxford-street,  W.C. 
Allen,  Charles  Joseph  Hyde,  F.L.S.,  G.S,,  Z.S. 

4,  Park-crescent,  Portland-place,  N.  W. 
Allen,  Daniel. 

69,  Union-street,  Byde,  Isle  of  Wight. 
*Ames,  George  Acland. 

Union  Club,  Trafalgar-square,  W.C. 
Angell,  Arthur,  jun. 

Hants  County  Laboratory,  Southampton. 
Ansted,  David  Thomas,  M.  A.  (Cantab.),  F.R.S.,  F.G.S.,  F.R.G.S.. 
F.C.P.S.,  Hon.  Mem.  B.I.B.A.,  Ord.  Hellen.  "  du  Sauveur" 
Eq.,  Soc.  Beg.  Sci.  Leod.  Corr.  Mem. 

The  Bed  House,  Melton,  Woodbridge. 
Anthony,  John,  M.D.,  M.R.C.P.L. 

6,  Greenfield-crescent,  Edgbaston,  Birmingham. 
Armstrong,  Thomas. 

Highfield  Bank,  Urmston,  Manchester. 
Atkinson,  John  Thomas. 

The  Quay,  Selby,  Yorkshire. 


Badcock,  John. 

2,  Banbury-road,  South  Hackney,  E. 
Baker,  Charles. 

244,  High  Holborn,  W.C. 

d  2 


xl  ROYAL   MICROSCOPICAL   SOCIETY 


Klected. 

1867 
1867 
1867 
1867 
1874 
1877 
1852 

1859 
1871 

1875 
1879 

1840 

1859 

1879 

1876 
1866 
1870 
1871 
1862 
1851 
1855 
1879 


Bannister,  Richarfl. 

The  Laboratory,  Inland  Revenue,  Somerset  House,  W.C. 
Barber,  John. 

31,  Bandolph-crescent,  Maida-ldll,  W. 
*Barker,  Samuel,  M.D.,  L.R.C.P.  Edin.,  M.R.C.S.,  F.M.S.,  &c. 
24,  Eaton-place,  Brighton. 
Barrett,  Charles  Albert,  M.R.C.S.  Edin.,  L.S.A.,  &c. 

Appleto7i  House,  Wallingford,  Berks. 
Bate,  George  Paddock,  M.D.,  F.R.C.S.E. 

2,  Northumberland  Houses,  King  Edward' s-rd.,  Hackney,  E. 
Baynes,  James,  Jr.,  E.C.S. 

Boyal  Chambers,  Scale-lane,  Hull. 
Beale,  Lionel  Smith,  M.B.  (Lond.),  F.R.C.P.,F.R.S.,  President  ; 
Professor  of  the  Principles  and  Practice  of  Medicine  in  King's 
College,  London,  and  Physician  to  the  Hospital. 
61,  Grosvenor-street,  W. 
*Beck,  Joseph,  F.R.A.S. 
31,  Cornhill,  E.C. 
Bed  well,  Francis  Alfred,  M.A.  (Cantab.). 
Fort  Hall,  Bridlington  Quay,  Hull. 
Beeby,  William  Hadden. 

14,  Bidinghouse-street,  W. 
Bell,   F.    Jeffrey,    B.A.,    F.Z.S.  ;    Professor    of   Comparative 
Anatomy  in  King's  College,  London. 

5,  Badnor-place,  Gloucester-square,  W. 

*Bell,  Thomas,  F.R.S.,  F.L.S.,  F.G.S. ;  Socc.  Hist.  Nat.  et 
Philomath.  Paris,  Acad.  Sc.  Philad.  et  Soc.  Hist.  Nat.  Bost. 
Corresp. 

The  Wakes,  Selborne,  near  Alton,  Hants. 
Bennet,  James  Lindsay. 

2,  Taviton-street,  Gordon-square,  W.C. 
Bennett,  Alfred  William,  M.A.,  B.Sc,  F.L.S. ;    Lecturer  on 
Botany  at  St.  Thomas's  Hospital. 

6,  Pa7-k  Village  East,  Begent's-park,  N.  W. 
Bentley,  Charles  Simpson. 

Hazelville  Villa,  Sunny  side-road,  Hornsey-rise,  N. 
*Berney,  John. 

61,  North-end,  Croydon,  Surrey. 
Berry,  John  G. 

West  Biding  Bank,  Huddersfield. 
Bcvington,  William  A. 

80,  Avondale-square,  Old  Kent -road,  S.E. 
*Bidlake,  John  Purdue,  B.A.,  F.C.P.,  F.C  S. 

339,  Essex-road,  Islington,  N. 
Bigg,  Henry  Heather,  Assoc.  Inst.  C.E. 

56,  Wimpole-street,  Cavendish-square,  W. 
Bishop,  George,  F.R.A.S.,  F.R.G.S. 

Meadow  Bank,  Ttvickenham. 
Blackham,  George  E.,  M.D. 

Dunkirk,  NY.,' U.S.A. 


ORDINARY   FELLOWS.  xli 

Blankley,  Frederick. 

15,  Belitha-iillas,  Barnsbury,  Islington,  N. 
Blenkins,   George  Eliezer,  F.E.C.S.,    F.E.H.S. ;  Dep.  Insp.- 
Gen.,  late  Surgeon-Major,  Grenadier  Guards. 

5,  Sandford-place,  ClieltenJiam. 
Bogue,  David. 

3,  *S^^.  Martin' s-place,  Trafalgar-square,  W.G. 
Bolton,  Thomas. 

17,  Ann-street,  Birmingham. 
Borland,  John. 

Bosehanlc,  KilmarnocJc,  N.B. 
Borradaile,  Charles. 

East  Hoathley,  HawMurst. 
*Bossey,  Francis,  M.D. 

Oxford-road,  Bedhill,  Surrey. 
Bouverie,|Eight  Hon.  Edward  Pleydell,  M.A.  (Cantab.),  F.E.S. 

Manor  House,  Market  Lavington,  Wilts. 
Bowman,  Frederick  Hungerford,  F.E.A.S.,  F.C.S.,  &c. 

Halifax,  Torkshire. 
Boyle,  William  Ansell. 

7,  MecMenburgh-square,  W.G.' 
Bradley,  Charles  Lawrence,  F.E.C.S.,  F.L.S. 

Thatched  House  Club,  St.  James' -street,  S.W, 
*Brady,  Sir  Antonio,  Kt.,  F.G.S.,  F.M.S.,  F.A.S.L. 

Maryland  Point,  Stratford,  Essex,  E. 
Braidwood,  Peter  Murray,  M.D.,  L.E.C.S.E. 

2,  Delamere-terrace,  South  Park-road,  Birkenhead. 
Braithwaite,  Eobert,  M.D.,  M.E.C.S.,  F.L.S. 

The  Ferns,  303,  Clapham-road,  S.  W. 
*Bramwell,  The  Eight  Hon.  Sir  George  William  Wilshere. 

10,  Hyde-park-square,  W. 
Bremner,  Alexander  Martin. 

3,  North  King's  Bench-walk,  Temple,  E.G. 
Brindley,  William. 

Pergola  House,  Denmark-hill,  S.E. 
*Brook,  George,  Ter. 

Fernbrook,  Huddersfield. 
*Browne,  Eev.  Robert  Heni-y  Nisbett,  M.A.  (Oxon.),  F.E.B.S. 
120,  Inverness-terrace,  Baysivater,  W. 
Browne,  Eev.  Thomas  Henry,  F.G.S.,  M.E.S. 

High  Wycombe,  Bucks. 
Browning,  John,  F.E.A.S.,  F.M.S. 

63,  Strand,  W.G. 
Brownlow,  George  John,  M.A.  (Cantab.) ;  Associate  of  King's 
College,  London. 

4,  ;S^^  Alban's-road,  Kensington,  W. 
Brushfield,  Thomas  Nadauld,  M.D.,  &c. 

County  Asylum,  Brookwoocl,  Woking,  Surrey. 
Bunting,  Frederick. 

1,  Westcdl-place,  Cheltenham. 


xlii  EOYAL   MICROSCOPICAL    SOCIETY 


ElecteJ. 
1868 

1860 
1855 
1876 
1860 


1879 
1878 
1870 
1874 
1879 
1848 

1867 
1861 

1879 
1852 
1851 
1879 
1867 
1863 
1868 
1867 
1879 


*Buru,  William  Barnett,  M.D.  (Lond.),  M.E.C.S. 

Ecdeshourne,  Bedford-hill-road,  Balham,  S.W. 
Burton,  Jolin. 

50,  Portland-road,  Nottingham. 
Burton,  John  Moulden,  F.R.C.S. 

Lee  Park  Lodge,  Lee,  S.E. 
*Butler,  Philip  John,  F.Z.S. 

55,  De  Beaiwoir-road,  N. 
*  By  water,  Witham  Matthew. 

5,  Hanover-square,  W. 


Campbell,  Francis  Maule. 

Bose  Hill,  Hoddesdon. 
Campion  Frank. 

The  Mount,  Dttffield-road,  Derhij. 
*Capel,  Charles  Cecil. 

North  Cray-place,  CMslehurst,  Kent. 
^Carpenter,  Alfred,  M.D.,  J.P. 

High-street,  Ch'oydon,  Surrey. 
Carpenter,  Henry  Sanders. 

BecMngton  House,  Weigliton-road,  Anerley,  S.E, 
Carpenter,  William  Beni'amin,  C.B.,  M.D.,  LL.D.,  F.R.S.,  L.S. 
and  G.S.,  Hon.  F.C.P.S. ;  Inst.  Fr.  (Acad.  Sci.),  Soc.  Biol, 
Soc.  Philomat.  Paris,  et  Soc.  Phil.  Amer.  Philad.  Corr.  Mem. 
56,  Begenfs-parlt-road,  N.W. 
Cartwright,  Samuel,  F.R.C.S. 

32,  Old  Burlington-street,  W. 
*Cattley,  Edward  Abbs. 

Care  of  Messrs.  Bopes  &  Co.,  5,  Jeffrey  s-sqnarc,  St.  Mary 
Axe,  E.C. 
Cazaux,  Denis  Blancq. 

61,  Finshury-jKirJc-road,  N. 
Cecly,  Robert,  F.R.C.S. 

Aylesbury. 
Chamberlain,  Thomas. 

11,  Dacre-road,  Forest-hill,  S.E. 
*Chandler,  George. 

15,  Coleman-street,  E.C. 
Chaplin,  Richard  Piper. 

Earlham,  Bahbicomhe-road,  Torquay. 
Ciaccio,  Dr.  Guiseppe. 

Bologna,  Italy. 
Codd,  Francis. 

51,  Duke-street,  Devonport. 
*Codrington,  Oliver,  M.R.C.S.  {Army  Medical  Bepartment). 
Fort  Pitt,  Chatham,  Kent. 
Cole,  Arthur  Charles. 

St.  Domingo  House,  Oxford-gardens,  Nofting-hill,  W. 


ORDINARY    FELLOWS. 


xliii 


Kleeted. 
1872 

1866 
1842 

1867 
1875 
1870 
1874 
1875 
1860 
1866 
1863 
1871 
1853 
1878 
1866 


1871 
1860 
1866 
1862 
1862 
1878 
1865 
1854 


Cole,  Walter  B. 

St.  John' 8-ter race,  Weymouth. 
Collins,  Charles. 

157,  Great  Portland-street,  W. 
Cooper,  William  White,  F.E.CS. ;  Surgeon-Oculist  in  Ordinary 
to  Her  Majesty  the  Queen. 

19,  Berheley-square,  W. 
*Coppock,  Charles,  F.M.S. 

109,  Grosvenor-road,  Highbury  Neio-parh,  N. 
Cowan,  Thomas  William. 

Comptons  Lea,  Horsham,  Sussex. 
Crisp,  Frank,  LL.B.,  B.A.,  F.L.S.,  &c. ;  Secretauy. 

5,  Lansdowne-road,  Notting-hill,  W. 
Crisp,  John  Shalders. 

Ashville,  Lewin-road,  Streatham,  S.W. 
Croft,  Lieut.  Eicharcl  Benyon,  E.N. 

Ware,  Herts. 
*Crofton,  Edward,  M.A.  (Oxon.). 

45,  West  Cromwell-road,  Earl's  Court-road,  S.W. 
Crook,  Thomas. 

3,  Grosvenor-villas,  Cleveland-road,  Surhiton. 
Crouch,  Henry. 

66,  Barhican,  E.C. 
Croydon,  Charles. 

Pato  Point,  Wilcove,  Torpoint,  Cornwall. 
Cundell,  George  Smith. 

Clarence  Lodge,  Clarence-road,  Clapham-parJc,  S.  W. 
Cunliffe,  Peter  G. 

The  Elms,  Handforth,  Manchester. 
Curties,  Thomas. 

244,  High  Holborn,  W.C. 


Dallinger,  Eev.  W.  H. 

The  Parsonage,  Woolton,  near  Liverpool. 
Dallmeyer,  John  Henry,  F.E.A.S. 

19,  Bloomshury-street,  W.C. 
Davis,  Charles. 

29,  Gloucester-place,  Portman-square,  W. 
*Davis,  George. 

Heathlands,  Bournemouth. 
Davis,  Henry. 

Wingate  House,  Haigh,  Wigan. 
Davis,  John. 

56,  Sutherland-gardens,  St.  Peter' s-parh,  W. 
Davison,  Thomas. 

248,  Bath-street,  Glasqow. 
'^Dayman,  Charles  Orchard,  M.A.  (Cantab.),  F.E.A.S. 

Merrie  Meade,  Millbruok,  Southampton. 


xliv 


KOYAL    MICROSCOPICAL   SOCIETY 


Klcclcd. 

1878 
1863 


1855 
1846 


1867 
1879 
1868 

1879 
1874 
1879 

1868 
1853 

1868 
1878 
1867 
1853 
1862 
1860 
1861 


Dcby,  .Tnlicn. 

72,  Warwick-gardens,  Kensington,  W. 
Do  Castro,  James  Cato. 

Care  of  G.  Carew,  Esq.,  15,  Southampton-street,  Blooms- 
hurif,  W.C. 
Do  Grave,  John  Francis,  M.E.C.P.  Lond.,  M.R.C.S. 
13,  Morland-road,  Croi/don. 
*Dc   La  lino,  Warren,  M.A.',  D.C.L.  (Oxon.),   Ph.D.,  F.R.S., 
F.R.A.S.,   F.C.S.,   Ord.  S.S/'"''-  Maur.  et  Lazar.  Ital.  Com., 
Leg.  Imp.  Honor,  et  Ord.  Imp.  Bras.  Bosae  Eq.,  Soc.  Pholog. 
Ed.iii.  et  Soc.  p>ro  Phys.  indag.  Berol.  Soc.  Honor.,  Acad.  Imp. 
Sci.  Pctrop.,  Soc.  Beg.  Set.  Ui)sal.,  Soe.  pro  fov.  Indust.  Nat.  et 
Soc.  Philom.  Par..,  Soc.  d'Agric.  et  de  Commerce  de  Caen,  et 
Soc.  Sci.  Nat.  Carol).  Mem.  Corr. 

73,  Portland-place,  W. 
Dohson,  Henry  Holmes. 

Holmesdale,  Ch'ange-parJc,  Ealing,  W. 
Douglas,  John  A. 

23,  Bentlei/street,  Bradford. 
Draper,  Edward  Thomson. 

12,  Buckingham-street,  Strand,  W.C,  and  Harlngeij-ixirk, 
Croxich  End,  N. 
Dreyfus,  Ludwig. 

181,  Adelaide-road,  St.  Johns-ioood. 
Drysdalc,  John  James,  M.D.E. 

36f<,  Bodncy-strect,  Liverpool. 
Duncan,  Peter  Martin,  M.B.  (Lond.),  F.R.S.,    F.G.S. ;    Pro- 
fessor of  Geology  in  King's  College,  London,  Acad.  Nat.  Sci. 
'Pldlad.  Corr.  Mem. 

4,  St.  George  s-terrace,  Beqen£s-park-road,  N.W. 
Durham,  Arthur  Edward,  F.H.C.S.,  F.L.S.,  i^c. 

82,  Broolc-strert,  Grosrcnor-square,  W. 
Dyster,  Frederick  Daniel,  M.D.,  F.L.S. 

Tenhy,  Pemhrolceshire. 


Eddy,  James  Ray,  F.G.S. 

The  Grange,  Carleton,  near  Shipton,  Yorkshire. 
Edmunds,  James,  M.D. 

8,  Graf  ton-street,  Piccadilly,  W. 
Edmunds,  Thomas  Wilcox. 

32,  Old  Change.  E.C. 
Elliott,  William  Timbrell. 

113,  Adelaide-road,  N.W. 
Ellis,  Septimus. 

Brnton  House,  Woodford,  Essex. 
*Elphinstone,  Howard  Warburton,  M.A.  (Cantab.),  F.L.S. 

2,  Stone-hnddings,  Lincoln  s-inn,  W.C. 
Emmens,  William. 

Naiiditat  Bank,  Old  Broad-street,  E.C. 


Elected. 


OKDINARY    FELLOWS.  xlv 

Evans,  Henry  Siigdcn,  F.C.S. 

Care   of  Evans  &  Co.,  GO,  Bartholomeio  Close,   London, 
KC. 
Eve,  Eichard  Wafford,  M.B.,  F.E.A.S. 

101,  Lewisham  High-road,  S.E. 


Fairey,  John  Wilkinson. 

Lovell,  Biddlesdown  Park,  Kenley,  Surrey. 
Farre,  Artliur,  M.D.  (Cantab.),  F.R.C.P.,  F.R.S. ;  Physician 
Extraordinary  to  the  Queen,  Physician  Accoucheur  to  H.R.H. 
the  Princess  of  Wales,  and  H.B.I.H.  the  Duchess  of  Edinhnnjh. 

18,  Albert  Mansions,  Victoria  street,  S.W. 
Festing,  Major  Augustus  Morton. 

6,  St.  Jean  D' Acre-terrace,  Devonport. 
*Finzil,  Conrad  William. 

Frankfort  Hall,  Clevedon,  Somerset. 
*Firniin,  Philip  Smith. 

Ladhroke,  Mortlake-road,  Keu\ 
Fischer,  Carl  F.,  M.D.,  F.L.S.,  F.G.S.,  Soc  Zovl.-Bot.  Vlndoh. 
Socius. 

Sydney,  N.S.  Wales.     Care  of  Oerich  d  Co.,  7,  Mincing- 
lane,  E.C. 
Fitch,  Frederick,  F.R.G.S. 

Hadleigh  House,  Highbury  New-parJc,  N. 
Fitch,  Frederick  George. 

17,  Canonbury-imrk  North,  N. 
FitzGerald,  Alexander. 

43.  Milbank-street,  Westminster,  S.W. 
Fowke,  Francis. 

40,  Nottingham-jylace,  W. 
Fox,  Charles  Jaraes. 

2G,  South  Molton-street,  Oxford-street,  W. 
Franipton,  Capt.  Cyril,  E.M. 

Forton  Barracks,  Gosport. 
Freckelton,  Ecv.  Thomas  Wesley. 

28,  Lonsdale-sqiiare,  Islington,  N. 
Freestone,  William  Lionel. 

63,  Navarino-road ,  Dalston,  E. 
Fuller,  William. 

Woodcote,  Epsom,  Surrey. 


Garnham,  John. 

123,  Bunhill-row,  E.C. 
*Gay,  Frederick  William. 

113,  High  Holborn,  W.C. 
Gent,  John  Henry. 

79,  Great  Tower-street,  E.C. 


Xlvi  ROYAL   MICEOSCOPICAL    SOCIETY 


Elected. 

1862 


1879 
1868 

1879 
1872 
1879 
1847 
1856 

1877 
1879 
1874 
1867 

1879 
1866 
1861 
1870 
1855 

1855 
1879 
1872 
1849 
1861 


*George,  Etlvvard. 

70,  Old  Brood-street,  City,  E.G.,  and  12,  Derhy-viUos, 
Forest-hill,  S.E. 
Gibbes,  Heneage. 

42,  ColvUle-terrace,  Bayswater,  W. 
*Gibbons,  William  Sydney. 

Melbourne,  Australia.     Care  of  C.  Eichnan,  78,  Clmrcli- 
street,  Camherwell,  S.E. 
Gibbs,  Alban  G.  H. 

82,  Portland-place,  W. 
Gibson,  Joseph  F. 

Clovelly,  Woodclmrch-road,  West  Hampstead,  N.  W. 
Gilburt,  "William  Hewett. 

48,  Wetlicrall-road,  South  Hachiei/,  E. 
Gillett,  William  Stedman,  M.A.,  F.R.A.S.,  F.R.H.S.,  &c. 
Harefield,  Bittern,  Southampton. 
*Glaisher,   James,   F.E.S.,   F.E.A.S.,    Pres.   Phot.   Soc,  Ord. 
Bras.  Bosae  Eq. 

1,  Dartmouth-place,  BlacJcheath,  S.E, 
*Godman,  Frederick  Du  Cane,  F.L.S. 
6,  Tenterden-street,  W. 
Goodall,  Thomas  Sorby. 

5,  Saint  Peter's- street,  Derby. 
Goodinge,  James  Wallinger. 

18,  Aldersgate-street.^  E.C. 
Gowlland,   Peter  Yeames',  F.E.C.S. ;    Surgeon    to   St.  MarFs 
Hospital. 

34,  Finshury-square,  E.C. 
Graham,  Walter. 

21,  Ludgate-hill,  Birmingham. 
*Gray,  William  John,  M.D. 

41,  Queen  Anne-street,  Cavendish-square,  W. 
Green,  Edward  Baker,  F.R.H.S. 

3,  Wliarf-road,  City-road,  N. 
Greenish,  Thomas. 

20,  New-street,  Dorset-square,  W. 
Griffith,  Eichard  Clewin,  M.E.C.S.,  F.E.G.S.,  F.Z.S.,  F.E.B. 
and  E.H.S.,  M.E.I. 

20,  Goioer-street,  W.C. 
Grove,  Edmimd. 

Saltburn-hy-the-Sea,  YorJcshire. 
Groves,  J.  William;  Demonstrator  of  Physiology  at  King's  College. 

55,  Bussell- square,  W. 
Guimaraens,  A.  de  Soiiza. 

50,  Loicden-road,  Herne-hill,  S.E. 
*Gurney,  Samuel,  F.L.S.,  F.E.G.S.,  &c. 

20,  Hanover-terrace,  Begenfs-parl.',  N.W. 
Guy,  William  Augustus,  M.B.  (Cantab.),   F.E.C.P.,  F.R.S. ; 
Physician  to  King's  College  Hospital. 

22,  Gordon-street,  Gordon-squore,  W.C. 


ORDINARY    FELLOWS. 


xlvii 


Elerted. 

1877 

1877 

1875 

1845  I 

1874 

1861 

1862 

1865 

1872 

1878 

1868 

1867 

1879 

1867 

1860 

1879 

1853 

1862 

1852 

1855 

1866 

1879 

1878 

1851 

1856 


Habirsbaw,  Frederick. 

6,  West  ASth-streef,  New  York,  U.S.A. 
Habirshaw,  Jobn,  M.D. 

6,  West  4:8th-street,  New  York,  U.S.A. 
Hamilton,  Jobn  James. 

South  Barrow,  BicJcley,  Kent. 
Handford,  George  Cbarlton. 

224,  King's-road,  Chelsea,  S.W. 
fHanks,  Henry. 

619,  Montgomery-street,  San  Francisco,  California,  U.S.A. 
Hardingbam,  George  Gatton,  F.E.B.S. 

33,  St.  George' s-square,  S.W. 
Hardy,  Mitcbell  Cbarles. 

6,  Tlie  Terrace,  Farquhar-road,  Upper  Norwood,  S.E. 
Harkness,  William. 

Laboratory,  Somerset  House,  W.C. 
Harris,  Edward. 

Bydal  Villa,  Longton-grove,  Sydenham,  S.E. 
Harrison,  Jobn  Simpson. 

Care  of  A.  Juhh,  Esq.,  Huddersfield. 
Harrop,  Edward  Davy. 

Launceston,  Tasmania. 
*Hartree,  William,  Associate  Inst.  C.E.,  F.Z.S. 

Carlton-villas,  Blachheath-parh,  S.E. 
Harvey,  Tbomas  Morton. 

89,  Lansdowne-road,  Notting-hill,  W. 
Helm,  Henry  James. 

Tlie  Laboratory,  Liland  Bevemie,  Somerset  Hovse,  W.C. 
Hennell,  Colonel  Samuel. 

Ventnor  Villa,  Ventnor,  Isle  of  Wight. 
Hepburn,  Jobn  Frankland. 

7,  Pancras-lane,  E.C. 

Hepburn,  Jobn  Gotcb,  LL.B.  (Lond.),  F.C.S. 

Baldwyns,  Bexley,  Kent. 
Hewitt,  Wbisson  Wbite. 

5,  Torriano-gardens,  Camden-toicn,  N.W. 
Hilton,  James. 

60,  Montague-square,  W. 
Hingeston,  Cbarles  Hilton. 

30,  Wood-street,  Cheapside,  E.G. 
*Hirst,  Jobn,  jun. 

Dobcross,  near  Manchester. 
Hitchcock,  Eomyn. 

150,  Nassau-street,  Neio  Yorh,  U.S.A. 
Hobson,  Amos. 

17,  Regent-street,  Waterloo-place,  S.W. 
Hogg,  Jabez,  M.E.C.S. 

1,  Bedford-square,  W.C. 
Hopgood,  James. 

Glapham-common,  S.  W. 

t  Correspouding  Fellow  . 


xlviii  ItOYAL    MICROSCOPICAL   SOCIETY 


Klccted. 
1867 

1874 
1876 
1873 
1868 
1863 
1872 
1853 
1864 
1853 


1861 
1867 
1863 

1867 
1867 
1840 

1867 

1872 
1875 
1862 
1868 


Hopkinson,  John. 

Wan-tfoi-d  Honse,  Watford. 
Home,  Kobert. 

Union-terrace,  Cheetham-hill,  Manchester. 
*Hovendeu,  Charles  William. 

95,  Citij-road,  E.G. 
*Hoveuden,  Frederick. 

Glenlea,  Thurlow-park-road,  Dulioich,  S.E. 
Howard,  Eobert  Luke. 

MacJcerye,  Harpenden,  St.  Albans. 
Hoyer,  Frederick. 

Care  of  Charles  Tyler,  Esq.,  317,  Hulloway-rd.,  Uolloway,  N. 
Hudson,  Charles  Thomas,  M.A.,  LL.D.  (Cantab.). 

Manilla  Hall,  Clifton,  Bristol. 
midson,  Eobert,  J^'.E.S.,  L.S.,  G.S. 

Clapham-common,  S.  W. 
Hudson,  William. 

13,  Stochwell-street,  Greenwich,  S.E. 
Huggius,  William,  D.C.L.  (Oxon.),  LL.D.  (Cantab.  &  Ediu.), 
F.E.S.,  F.E.A.S.,  Math.  D.  Lugd.  Bat.,  Ord.  Imp.  Bras. 
Bosae.  Coin.,  Inst.  Fr.  (Acad.  Sci.),  Acad.  Lync.  Bomae  et  Soc. 
Beg.  Sci.  Gott.  Mem.  Corr.,  Socc.  Beg.  Sci.  Hafn.,  Physiogr. 
Lund.,  Beg.  Boie.  Maroh.,  Beg.  Buhl,  et  Lit.  Phil.  Mane. 
Soc.  Honor. 

Upper  Tulse-hill,  S.W. 
Hughes,  Eev.  John  Gwynne. 

Maldon,  Esse.v. 
Humphrys,  John  James  Hamilton. 

5,  New-square,  Lincoln' s-inn,  W.C. 
Hunt,  William  Henry  Brooks. 

23,  Eversholt-street,  Oakley-square,  N.W. 

Ibbetson,  George  Augustus,  F.E.C.S.,  F.G.S. 

19a,  Hanover-square,  W. 
*Lice,  Joseph,  F.L.S.,  G.S.,  C.S.,  &c. 

29,  St.  Stephen' s-avenue.  Shepherd' s-hush,  W. 
*Ince,  WiUiam  Heniy,  F.L.S. 

Burleigh  House,  Baron's  Court-road,West  Kensington, S.  W. 
Ingpen,  John  Edmund. 

7,  The  Hill,  Putney,  S.W. 

Jackson,  B.  Daydon,  F.L.S. 

30,  Stochioell-road,  S.W. 
Jackson,  Charles  Ijoxton. 

Hill  Fold,  Sharpies,  Bolton. 
Jaques,  Edward,  B.A. 

Oflice  of  Woods,  &c.,  1,  Wliitehall-place,  S.W. 
Jayaker,  Atmaram  Sadashwa,  L.E.C.P.  London. 

Muscat,  Arabia. 


ORDINARY    FELLOWS.  xlix 


*Jeula,  Henry,  F.K.G.S.,  F.A.S.L.,  &c. 

West  Combe  Lodge,  BlacJcheath,  S.E. 
Jolinson,  Arthur  Jukes,  M.D. 

Corner  of  William  and  Toung-street,   Yorkville,  Toronto, 
Canada. 

*  Johnson,  David. 

Grosvenor-road,  WrexJiam. 
Johnson,  Matthew  Hawkins,  FE.G.S. 

379,  Euston-road,  N.  W. 
Jones,  Ai-thur  O'Brien,  F.E.C.S. 

The  Shrubbery,  Epsom,  Surrey. 

*  Jones,  Emanuel  Wilkins,  F.E.A.S. 

53,  Cowley-road,  North  Brixton,  S.W. 
Jones,  George  Horatio, 

57,  Great  Bussell-street,  Bloomsbury,  W.C. 
Jones,  Henry  Williams. 

183,  Park-road,  Aston,  near  Birmingham. 
Jones,  Joseph  Birdsall. 

Hie  AthencBum,  Liverpool. 
Jones,  William  Heniy. 

37,  Mincing-lane,  E.G.,  and  2,  Bye-hill-park,  Peckham 
Bye,  S.E. 
Jordan,  John. 

6,  Notting-hill-square,  W.,  and  3,  Victoria-street,  S.W. 
Joshua,  William,  F.L.S. 

Cirencester. 


Kelly,  George. 

9,  Sutherland-gardens,  Kilburn-road,  N.  W. 
Kemp,  Eohert. 

60,  Windsor-road,  Upper  Holloway,  N. 
Kent,  William  SaviU,  F.L.S.,  F.Z.S. 

46,  Osnaburgh-street,  BegenVs-park,  N.W. 
Kerr,  Walter. 

316.  Fidham-road,  S.W. 
Kershaw,  William  Wayland,  M.D. 

10,  Claremont-crescent,  Surbiton,  Surrey. 
King,  Edwin  Holborow  Green,  M.E.C.S.,  L.D.S. 

KiUcott,  Godalming,  Surrey. 
King,  Eobert. 

Fern  House,  Upper  Clapton. 
Kingsbury,  Francis  John. 

11,  Loughhorough-park-road,  Brixton,  S.W. 
^Kippist,  Eichard,  A.L.S. ;  Acad.  Nat.  Sc.  Philad.  Corresp, 

Linnean  Society,  Burlington  House,  W. 
Kirby,  Arthur  Eaymond. 
I  11a,  Neuj-square,  Lincolns-inn,  W.C. 

1879  '   Knight,  Thomas  Edward  Wilmot. 
1  44,  Essex-street.  Strand,  W.C. 

VOL.  II.  e 


1  ROYAL  MICEOSCOPICAL  SOCIETY 


Elected. 

1878 


1851 
1851 
1877 
1874 
1861 
1865 

1864 

1855 
1842 
1874 
1864 
1876 
1866 
1871 
1866 
1867 
1854 

1879 
1879 

1861 


Kyngdon,  Francis  Boughton. 

221,  Darlinghurst-road,  Sydney,  N.S.  Wales. 


Ladd,  WiUiam,  F.E.A.S. 

12,  Beak-street,  Begent-street,  W. 
Ladds,  John. 

8,  Kent-gardens,  Castle  Hill  ParJc,  Ealing,  W. 
*Lambert,  Charles  Joseph. 
29,  Parh-lane,  W. 
Lancaster,  William  James,  F.R.A.S.,  &c. 

Stanley  Villa,  Church  Hill-road,  Handsworth,  Birmingham. 
Lang,  Major  Frederick  Henry. 

St.  Katherines,  Barhstone,  Dorset. 
Lankester,  Edwin  Bay,  M.A.  (Oxon.),  F.E.S. ,-  Prof,  of  Zoology 
and  Comparative  Anatomy  in  University  College,  London. 
11,  Wellington  Mansions,  North  Bank,  N.W. 
Lawson,  Marmaduke  Alexander,  M.A.,  F.L.S. ;   Professor  of 
Botany  in  the  University  of  Oxford. 
Botanic-gardens,  Oxford. 
*Leaf,  Charles  John,  F.L.S.,  F.S.A.,  F.R.G.S. 
Old  Cliange,  E.G. 
Lealand,  Peter  Henry. 

170,  Euston-road,  Euston-square,  N.W. 
Leather,  Samuel  Petty,  C.E. 

Gas  Works,  Burnley,  Lancashire. 
*Lee,  Henry,  F.L.S.,  F.G.S.,  F.Z.S. 
Tlie  Waldrons,  Croydon. 
Lettsom,  William  Garrow. 

2,  Tlmrloiv-place,  Loioer  Noricood,  S.E. 
*Lewis,  Richard  Thomas. 

I,  Loiondes-terrace,  Knightshridge,  S.W. 
Lindsay,  James  Ludovic,  Lord,  F.R.S.,  P.R.A.S. 

47,  Brook-street,  W.,  and  Bun  Edit,  Aberdeen. 
Lovibond,  Joseph  Williams. 

St.  Anne-street,  Salisbury. 
Loy,  William  Thomas. 

II,  Garrick-chambers,  Garrick-sfreet,  Covent-garden,  W.C. 
*Lnbbock,  Sir  John,  Bart.,  M.P.,  F.R.S.,  F.L.S.,  F.G.S.,  Trust. 

Brit.  Mus.,  (&c. 

High  Elms,  Bromley,  Kent. 
Lucas,  Charles. 

St.  Thomns's  Hospital,  S.W. 
Lyon,  Thomas  Glover. 

85,  Asylum-road,  Peckliam,  S.E. 


Mackrell,  John. 

B,  Victoria-rood,  Clnpham-common,  S.W. 


OEDINARY   FELLOWS.  11 

Makins,  George  Hogarth,  M.R.C.S.,  F.C.S. 

Danesfield,  Walton-on-  Thames. 
Makins,  Walter  K. 

Westhor2)e  House,  Hendon,  N.  W. 
Mclutire,  Samuel  John. 

22.  Bessborough-gardens,  Pimlico,  S.W. 
*Maiicliester,  William  Drogo,  Duke  of,  F.Z.S. 

1,    Great   Stanhope-street,  Mayfair,    W.,   and  Kimholton 
Castle,  St.  Neot's,  Herts. 
Manners,  George. 

1,  Lansdowne-gardens,  Croydon,  Surrey. 
1867   *Manniug,  WiUiam. 

21,  Bedcliffe-gardens,  South  Kensington,  S.W. 
Martin,  Nicholas  Henry. 

29,  Mosley-street,  Neivcastle-on-Tyne. 
MaskeU,  William  Miles,  J.P. 

Christchurch,  Canterbury,  New  Zealand. 
*Mason,  Philip  Brookes, 
Burton-on-  Tren  t . 
Matthews,  John,  M.D. 

30,  ColebrooTce-row,  Islington,  N. 
May,  John  William,  Consul  General  for  the  Netherlands. 

Arundel  House,  Percy-cross,  Fulham-road,  S.  W. 
Mayall,  John,  jnn. 

224.  Begent-street,  W. 
Mayall,  John  Edwin,  F.A.S.L. 

Tlie  StorFs  Nest,  Lancing,  Sussex. 
Meade,  The  Hon.  Robert  Henry,  F.R.G.S. 

Foreign  Office,  and  32,  Belgrave-square,  S.  W. 
Mercer,  A.  Clifford,  M.D. 

33,  Bichmond-terrace,  Clapham-road,  S.W. 
Mestayer,  Richard,  F.L.S. 

7,  Buckland-crescent,  Belsize-parh,  N.W. 
Michael,  Albert  Davidson,  F.L.S. 

3  £&  4,  Great  Winchester-street,  B.C. 
Millar,  John,  L.R.C.P.  Edin.,  F.L.S.,  and  G.S. 

Bethnall  House,  Cambridge-road,  E. 
Mills,  Rev.  Lewis  George,  LL.D. 

The  Bcctory,  Creggan,  Crossmaglen,  Armagh,  Ireland. 
Moginie,  William. 

26,  Lichfield-grove,  Finchley,  N. 
*Moore,  Joseph. 

Bydal  Mount,  Cha7»piou-hill,  Camberwell,  S.E. 
Moreland,  Richard,  jun.,  M.I.C.E. 

3,    Old-street,   St.  Luhes,  B.C.,   and   4,   The  Quadrant, 
Highbury. 
*Morricson,  Colonel  Robert. 

Oriental  Cluh,  Hanover-square,  W. 
Morris,  John,  F.Z.S. 

13,  Parlc-street,  Grosvenor-square,  W. 

e  2 


Hi  ROYAL   MICROSCOPICAL   SOCIETY 


Klected. 

1876 

1871 

1850 


1879 
1879 
1849 

1855 


1867 
1878 
1879 
1856 
1876 

1840 


Morris,  William,  M.D. 

Sydney,  New  South  Wales.     Care  of  J.  B.  Watt  d;  Co., 
5,  East  India-avenue,  E. 
Mostyn,  Charles. 

Elmley  House,  Gh-ove-road,  Surbiton,  S.W. 
Mummery,  John  Eigden,  F.L.S. 

10,  Cavendish-place,  Cavendish-square,  W. 


Nachet,  A. 

17,  Bue  St.  Severin,  Paris. 
Nichols,  George  Livesey. 

54,  Old  Broad-street,  E.C. 
Noble,  John,  F.R.H.S. 

50,  Westhoiirne-terrace,  Hyde-parh,  W.,  and  ParJc-place, 
Henley-on-  Thames. 
*Noble,  Captain  William,  F.R.A.S. 

Forest  Lodge,  Maresfield,  Sussex. 


*  Oakley,  John  JeflEryes. 

24,  Sussex-gardens,  Hyde-park,  W. 
O'Hara,  Eichard,  Lieut.-Col. 

West  Lodge,  Galioay. 
Ord,  WiUiam  Millar,  M.D.,  F.R.C.P. 

7,  Brook-street,  Grosvenor-square,  W. 
Osborne,  The  Hon.  and  Eev.  The  Lord  Sidney  Godolphin,  M.  A. 

Sidmouth. 

Osier,  William,  M.D. ;  Institute  of  Medicine,  McGill's  College, 

Montreal.      Care   of  Messrs.    Williams  &  Norgate,  14, 

Henrietta-street,  Covent-garden,  W.C. 

Owen,  Eichard,  C.B.,  M.D.,  D.C.L.,  LL.D.,  F.E.S.,   F.L.S., 

F.G.S.,  F.Z.S.,  Director  of  the  Natural-History  Department, 

British  Museum,   Coll.  Beg.   Chir.  Hib.  et  Soc.  Beg.  Edin. 

Soc.  Honor.,  Ord.  Bortiss.  "  Pour  le  Merite"  Eq.,  Inst.  Fr. 

(Acad.  Sci.)  Par.  Adsoc.  Extr.,  Acadd.  Imp.    Sci.   Vindob., 

Petrop.,  et  Soc.   Imp.   Sc.  Nat.   Hist.  Mosq.,    Acadd.  Beg. 

Sci.   Berol.,    Taiirin.,    Madrit.,    Holm.,    Monach.,   Neapol., 

Bruxell.,  Bonon.,  Instit.  Beg.  Sc.  Amstelod.,  Socc.  Beg.  Sc. 

Hafn.,  Upsal.,  Acad.  Amer.  Sc.  Bost.  Socius,  Soc.  Philomath. 

Paris.  Corresp.,  Geor.  Florent,  Soc.  Sc.  Harlem.,  Trajectin., 

Phys.   et   Hist.  Nat.   Genev.,  Acadd.  Lync.   Bomce,  Patav., 

Panorm.,  Gioen.  Nat.  Scrutat.  Berol.,  Instit.  Wetter.,  Philad., 

Nov.-Ebor.,   Bost.,  Acad.  Beg.  Med.  Paris.,  Soc.  Imp.  et  Beg. 

Med.  Vindob.  Adsoc.  Extr. 

British  Museum,  W.C,  and  Sheen  Lodge,  Mortlalte,  S.W. 


Elected. 


ORDINARY   FELLOWS.  liii 

*Owen,  Major  Samuel  Eicliard  John. 

Care  of  J.  F.  Collingwood,  Esq.,  Anthropological  Institu- 
tion, 4,  St.  Martinis-lane,  W.C. 
Oxley,  Frederick. 

8,  Crosby-square,  E.G. 


Page,  JuHus,  F.E.A.S. 

63,  South-street,  Greenwich,  S.E. 
Palmer,  Thomas,  B.Se. 

Homeleigh,  Loicer  Gamden,  Ghislehiirst. 
Parker,  T.  Jeffery,  B.Sc. 

Sproxton,  Brodrick-road,  Upper  Tooting,  S.W. 
Parker,  William  Kitchen,  F.R.S.,  F.L.S.,  F.Z.S.,  King's  Coll. 
Lond.  et  Phil.  Soc.  Cantah.  Sac.  Honor.,  Acad.   Sci.  Nat. 
Philad.  Soc.  Corr. 

36,  Glaverton-street,  S.W. 
Parkinson,  William  Coulson. 

18,  Garleton-road,  Tufnell-park  West,  N. 
Paton,  George  Lauchland. 

34,  Bichnond-terrace,  Clapham-road,  S.W. 
Pearse,  George  Edmund  Legge,  M.E.C.S. 

Markham  House,  King's-road,  Chelsea,  S.  W. 
*Peek,  Sir  Henry  WiUiam,  Bart.,  M.P.,  &c. 

Wimbledon  House,  S.  W. 
*Perigal,  Henry,  F.E.A.S. 

9,  North-crescent,  Bedford-square,  W.C. 
*Peters,  WiUiam,  F.E.A.S.,  F.E.B.S.,  F.Z.S. 

Ashfold,  Crawley,  Sussex. 
*Pickersgill,  William  Cimliffe,  F.E.H.S. 

Blendon  Hcdl,  Bexley,  Kent. 
Pidgeon,  Daniel. 

Winchester  House,  30,  Cheyne-walk,  Chelsea,  S.  W. 
Piggot,  Joseph  Allen. 

Bedford. 
Pillischer,  Moritz. 

88,  Neic  Bond-street,  W. 
Pitchford,  Edward  Beaumont. 

Varnish  Works,  Egham,  Surrey. 
Pittock,  George  Mayris,  M.B.  (Lond.). 

23,  Cecil-square,  Margate. 
Plomer,  George  Daniel. 

48,  Springfield-road,  St.  John's-ioood,  N.  W, 
Pochin,  Percival  Gerard. 

Grove  House,  Tottenham. 
Pocklington,  Heni-y. 

Cedar-grove,  Armley,  Leeds. 
Potter,  George. 

42,  Grove-road,  Upper  Holloway,  N. 


liv 


ROYAL   MICROSCOPICAL   SOCIETY 


Elected. 

1840     Powell,  Hugh. 

170,  Euston-road,  Euston-square,  N.W. 

1867  *Prescott,  Sir  George  Eendlesham,  Bart.,  F.Z.S. 
Isenhurst,  Hawkhurst,  Sussex. 

1878  Price,  George  Peters,  jun. 
Tandridge  House,  The  Avenue,  Elmers,  Surhiton. 

1840      Pritchard,  Eev.  Charles,  M. A.  (Cantab.),  F.E.S.,  F.K. A.S.,  F.G.S. 
F.C.P.S.,  Savilian  Professor  of  Astronomy,  Oxford. 
9,  Keble-terrace,  Oxford. 

1879  Pritchard,  Urban,  M.D. 
4,  George-street,  Hanover-square,  W. 

1851     Prothero,  Thomas,  F.S.A.,  F.E.B.S.,  &c. 

16,  Cleveland-gardens,  Bayswater,  W. 
1879    *Puleston,  John  Henry,  M.P. 

Westminster  Palace  Hotel,  S.W. 

1868  Puttick,  Alfred  James. 
26,  King-street,  Covent-garden,  W.G. 


1874  Eadford,  William,  M.D. 
Sidmouth. 

1868  *Eamsden;  Hildebrand,  M.A.  (Cantab.),  F.L.S. 
Forest  Rise,  Walthamstoiv,  Essex,  N.E. 

1878     Eaynor,  George. 

78,  Great  Cloiues-street,  Loiver  Broughton,  Manchester. 
1852     Eead,  Eev.  William,  M.A.,  F.E.A.S. 

Worthing. 
1862      Eeade,  George, 

Fern-hill,  Wliiihij. 
1877     Eedmayne,  John  Thomas,  L.E.C.P.  Edin.,  M.E.C.S.  Edin. 

Astleij  Bank,  Bolton. 

1869  Eedpath,  Henry  Syme. 

Sydenham,  S.E. 
1864     Eeeves,  Walter  Waters,  Assistant-Secretary. 

30,  Ashhurnham-grove,  Greenwich,  S.E. 
1861    *Eichards,  Edward. 

289,  Gamhenvell  New-road,  S.E. 

1875  Eoberts,  Samuel  Hackett. 

33,  King-street,  Cheapside,  E.G. 
1871      Eogers,  John. 

4,  Tennyson-street,  Nottingham. 
1873     Eogers,  Thomas. 

Selmeston,  Thurlow-parh-road,  West  Dulwich,  S.E. 
1867    *Eogerson,  John. 
1871      Eoper,  Charles,  M.R.C.S.,  &c. 

7,  Ghichester-place,  Southernhay,  Exeter. 
1852    *Eoper,  Freeman  Clark  Samuel,  F.L.S.,  G.S.,  Z.S. 

Palgrave  House,  Easthourne,  Sussex. 


ORDINARY    FELLOWS.  Iv 

Koper,  Henry  John. 

5,  Lausanne-road,  Pechham,  S.E. 
Eothery,  Henry  Cadogan,  M.A.  (Cantab.),  F.L.S.,   M.R.S.L., 
M.R.I. 

94,  Gloucester-terrace,  Hyde-park,  W. 
Eoyston-Pigott,  George  West,  M.A.,  M.D.  (Cantab.),  Coll.  Eeg. 
Med.  Soc,  F.C.P.S.,  F.R.S. 

Hartley  Court,  Beading,  Berks. 
Ruffle,  George  William. 

131,  Blackfriars-road,  S.E. 
*Rumble,  Thomas  William,  C.E.,  Assoc.  Inst.  Naval  Architects. 
Vauxhall  Water  Coinpany,  Sumner-sireet,  Southwark,  S.E. 
*Eylands,  Thomas  Glazebrook,  F.L.S.,  F.G.S.,  F.R.A.S. 
Highfields,  Thelwall,  near  Warrington. 


Salkeld,  Lieut.-Colonel  Joseph  Carleton. 
29,  St.  James' -street,  S.W. 
*Sanders,  Alfred,  M.R.C.S.,  F.L.S.,  F.Z.S. 

2,  Clarence-place,  Gravesend,  Kent. 
*Saunders,  Charles. 

Airy-hill,  Whitby. 
Sawyer,  George  D. 

55,  Buckingham-place,  Brighton. 
Schlesinger,  Henry. 

5,  Kensington-park-gardens,  W. 
Shadbolt,  George. 

Beechcroft,  Camden-park,  Chislehurst,  Kent. 
Sharpe,  George  Young. 

34,  High-street,  Notting-hill,  W. 
Shepheard,  Thomas. 

Kingsley  Lodge,  Cliester. 
Shuter,  James  Legasick,  F.R.A.S. 

33,  Farringdon-street. 
Sigsworth,  John  Cretney. 

18,  Chaucer-road,  Herne-hill,  S.E. 
*Silver,  Hugh  Adams,  Assoc.  Inst.  C.E. 

Hillside,  Chislehurst,  Kent. 
Simpson,  Charles  Turner. 

14,  Cormvall-gardens,  South  Kensington,  S.W. 
Simpson,  Rev.  David,  M.A.  (Cantab.). 

45,  Bue  Malesherhes,  Lyons,  France. 
Slack,  Henry  James,  F.G.S. 

Ashdoion  Cottage,  Forest-roio,  Sussex. 
Sleeman,  Rev.  Philip  R. 

Bichmond-hill,  Clifton,  Bristol, 
Smart,  John  Naish. 

3,  Brunswick-place,  Sivansea. 


Ivi  ROYAL   MICEOSCOPICAL   SOCIETY  : 


Elected. 

1864 
1859 
1866 
1874 
1866 

1864 
1877 
1857 
1879 
1854 
1861 
1860 
1876 

1867 
1854 
1871 
1879 
1863 
1850 


1870 
1840 


*Smitli,  Basil  Woodd,  F.R.A.S. 

Branch  Hill  Lodge,  Hampstead-heath,  N.  W. 
Smith,  James,  F.L.S. 

233,  Dalston-lane,  Haclcney,  E. 
*Smith,  Joseph  Travers,  F.R.B.S. 

4,  Haymond' s-huildings,  Gray  s-inn,  W.C. 
Smith,  Rowland  Dunn,  M.R.C.S.  Edin. 
1,  Clapton-square,  E. 
*Sorby,  Henry  Clifton,  LL.D.,  F.R.S.,  P.G.S.,  F.L.S.,  F.Z.S., 
Soe.  Min.  Petrop.,  Soc.  Holland.  Harl.  Sociiis.,  Acad.  Sci.  Nat. 
Philad.  et  Lye.  Hist.  Nat.  Nov.  Ebor.  Corr.  Mem. 
Broomfield,  Sheffield. 
*Spawforth,  Joseph. 

Sandall  Cottage,  Hornsey-rise,  N. 
Spencer,  James. 

South-street,  Greenicich,  S.E. 
Spencer,  Thomas,  F.C.S. 

32,  Euston-square,  N.W. 
Spicer,  Robert  Henry  Scanes,  B.Sc. 

14,  Sydney-street,  S.W. 

Spurrell,  Flaxman,  L.R.C.P.  Edin.,  F.R.C.S.,  &c. 

Belvedere,  Kent,  S.E. 
Stephenson,  John  Ware,  F.R.A.S.,  Tbeasurer. 

186,  Clapham-road,  S.W. 
Steward,  James  Henry. 

406,  Strand,  W.C. 
Stewart,  Charles,  M.R.C.S.,  F.L.S.,  Secretary. 

25,  Albert-square,  Clapham-road,  S.  W.,  and  St.  Thomas's 
Hospital,  S.E. 
Stoker,  George  Naylor. 

The  Laboratory , Inland  Revenue  Office,  Somerset  Hou8e,W.G. 
*Streatfield,  John  Fremlyn,  F.R.C.S. ' 

15,  Upper  Brook-street,  W. 
Stuart,  John. 

164,  New  Bond-street,  W. 
Stubbing,  John,  F.G.S. 

Chester  Cottage,  Old-lane,  Halifax. 
*Suffolk,  William  Thomas. 

Stettin  Lodge,  St.  Faith's-road,  Lower  Nonvood,  S.E. 
Symonds,  Frederick,  F.R.C.S.,  F.M.S. 

35,  Beaumont-street,  Oxford. 


*Tebbitt,  Walter. 

Elmhurst,  Cavendish-road,  Clapham-parJc,  S.W. 
Tennant,  James,  F.G.S,  C.S.,  M.S.,  Z.S. ;  Fellow  of  the  Geo- 
graphical Society   of  France,  Professor  of  Mineralogy   at 
King's  College,  London. 
^4:9,  Strand,  W.C. 


Elected. 


Oil  DINAR  Y    FELLOWS.  Ivii 

Terry,  William,  F.R.H.S.,  F.Z.S. 

Peterborougli  House,  Fiilham,  S.W. 
*Tliompson,  Frederick,  F.A.S.L. 

South-parade,  Wakefield. 
Tingle,  Thomas,  F.L.S. 

Apothecaries'  Hall,  Blackfriars,  E.C. 
Tolles,  Eobert  B. 

48,  Hanover-street,  Boston,  U.S. 
Townley,  James,  L.R.C.P.  Edin.,  F.R.C.S.,  F.L.S. 

302,  Kennington-parh-road,  S.E. 
*Towiisend,  .Tolin  Siimsion. 

Stamford  Lodge,  St.  Johns,  Sevenodks,  Kent. 
Truman,  Edwin,  M.K.C.S. ;  Dentist  to  Her  Majesty's  Household. 

23,  Old  Burlington-street,  W. 
Tulk,  John  Augustus,  M.A,  (Cantab.),  M.R.C.P.  Lond. 

Burton  Lodge,  Staines-road,  Ticickenham. 
Tupholme,  John  Thomas. 

1,  Coleherne-terrace,  West  Brompton. 
Turner,  William  Barwell,  F.C.S. 

55,  Reginald-terrace,  Chapeltown-road,  Leeds. 
Tyer,  Edward,  C.E.,  F.R.A.S.,  F.R.G.S.,  Assoc.  Inst.  C.E. 

32,  Bussell-square,  W.C. 
*Tyler,  Charles,  F.L.S.,  F.G.S. 

317,  Holloway-road,  Holloivay,  N. 
*Tyler,  George,  F.R.G.S. 

317,  Holloway-road,  Holloway,  N. 
Tyler,  Sir  James,  F.L.S.,  F.Z.S.,  F.R.B.  and  E.H.S. 

Pine  House,  Holloway,  N. 
*Tyler,  Rev.  WiUiam. 

247,  Hachiey-road,  N.E. 

*Vanner,  William. 

Camden-icood,  Chislehurst,  Kent. 
*Van  Voorst,  John,  F.L.S.,  F.Z.S. 
1,  Paternoster-row,  E.G. 
Vezey,  John  Jewell. 

39,  *S'^  Donatt's-road,  New  Cross,  S.E. 
*Vicary,  William,  F.G.S.,  F.M.S. 

The  Priory,  Colleton-crescent,  Exeter. 
Vinen,  Edward  Hart,  M.D.,  M.R.C.S.,  F.L.S. 

17,  Chepstoio -villas,  Bayswater,  W. 
Vize,  Rev.  John  Edward,  M.A. ;  Hon.  Mem.  Woolhope  Natu- 
ralists' Field  Cluh,  Hon.  Corr.  Mem.  Cryptogamic  Society  of 
Scotland. 

Forden  Vicarage,  Welshpool. 

Wain,  Thomas. 

13,   WarwicJc-street,  Regent-street,    W.,  and   Shruhlands, 
Hersham,  Esher,  Surrey. 


Iviii  ROYAL   MICROSCOnCAL   SOCIETY 


Elected. 

18G3 
1867 
1869 
1877 
1862 
1879 
1878 
1872 
1861 
1852 
1840 
1861 
1864 
1868 
1850 
1867 
1867 
1867 
1866 
1879 
1866 
1879 
1874 
1879 
1857 


Walker,  Frederick. 

Heyivood,  Tenhy. 
Walters,  James  Hopkins,  M.R.C.S. 

43,  Castle-street,  Beading. 
Ward,  Frederic  Henry,  M.R.C.S. 

Springfield,  near  Tooting,  S.W. 
Ward,  Eev.  James  Clifton,  F.G.S. 

Kesioick,  Cumberland. 
Ward,  John  Whitely. 

South  Royde,  Halifax,  Yorhsliire. 
Watson,  Thomas  E. 

2,  Clifton-place,  Newport,  Mon. 
Watts,  Eev.  G.  E.,  M.A. 

Kingsivorth  Vicarage,  Dunstable,  Herts. 
Webb,  Henry  Eichard,  J.  P. 

Epeira,  Lyttelton,  Canterbury,  New  Zealand. 
Wells,  John  Eobinson,  M.D.,  F.E.C.S. 

20,  Fitzroy-street,  Fitzroy-square,  W. 
West,  Tuflfen,  F.L.S. 

Frensham,  near  Farnham,  Surrey. 
Westley,  William, 

24,  Begent-street,  S.W. 
Westwood,  William  Henry. 

Oatlands-park,  Weybridge,  Surrey. 
Wheeler,  Edmund,  F.E.A.S. 

48,  Tollington-road,  Holloivay,  N. 
Wheldon,  John. 

58,  Great  Queen-street,  Lincoln' s-inn-fields,  W.C. 
White,  Charles  Frederick. 

42,  Windsor-road,  Ealing,  W. 
White,  Eobert  Owen,  M.I.C.E. 

The  Priory,  Leioisham,  S.E. 
White,  Thomas  Charters,  M.E.C.S.,  L.D.S. 

32,  Belgrave-road,  S.W. 
Whitelock,  Eev.  Benjamin,  M.A.  (Cantab.). 

Lealands,  Groombridge  (Sussex),  near  Timhridge  Wells. 
*Whitling,  Henry  Townsend,  M.R.C.S. 

53,  High-street,  Croydon,  Surrey. 
Whittell,  Horatio  Thomas. 

Edgbaston  House,  Adelaide,  South  Australia. 
Wight,  James  Ford. 

Grazeley,  Gipsy-hill,  Upper  Norwood,  S.E. 
Williams,  George. 

1,  Bevonport-road,  Shepherd' s-hush,  W. 
Williams,  John  Eailton. 

59,  Albion-road,  Stolce  Newington,  N. 
Willmott,  Collis. 

Triangle,  Hackney,  E. 
Wilson,  Eichard,  M.E.I. 

80,  Old  Broad-street,  B.C. 


Elected. 
1879 

1857 
1861 
1842 
1879 
1850 
1878 


1859 


1879 


OEDINAPvY   FELLOWS.  lix 

Wilson,  Samuel  King,  M.E.I. 

3,  Portland-terrace,  Begent's-parlc,  N.W. 
Wiltshire,  Eev.  Thomas,  M.A.,  F.L.S.,  F.G.S. 

25,  Gi-anville-parh,  Lewisham,  S.E. 
Winstone,  Benjamin. 

53,  Russell-square,  W.G. 
Wood,  Frederick,  F.R.C.S. 

13,  Marine-square,  Brighton. 
Woodall,  Robert. 

1,  Marlbro-terrace,  Maple-road,  Penge,  S.E . 
*Woodhouse,  Alfred  James,  L.D.S. 

1,  Hanover-square,  W. 
Woods,  George  Arthur,  L.R.C.P.,  M.E.C.S.,  &c. 

57,  Houghton-street,  Southport. 


Tool,  Henry,  F.Z.S. 

Oalcfield,  Weyhridge,  Surrey. 


Zeiss,  Carl. 

Jena,  Germany. 


Ix  110  YAL   MICROSCOPICAL   SOCIETY 


E'ectei  HONORARY  FELLOWS. 

1878  Abbe,  E. 

Jena. 

1879  Agassiz,  A. 

Camhridge  (Mass.),  U.S. 
1879      Archer,  W. 

Dublin. 
1879     Balbiani,  E.  G. 

Paris. 
1879      Bary,  A.  de. 

Strasshurg. 
1879     Beneden,  P.  J.  van. 

Louvain. 
1879     Berkeley,  Eev.  M.  J. 

Sibbertoft,  Market  Harborough. 
1869     Busk,  G. 

London. 
1879     Butscbli,  0. 

Heidelbe7-g. 
1876      Castracane,  Conte  Ab.  F. 

Fano  (Italy). 
1879     Cienkowski,  L. 

Kharkoff. 
1879     Cleve,  P.  T. 

Upsala. 
1879     Cohn,  F. 

Breslau. 
1879     Cornu,  M. 

Paris. 
1879      Dodel-Port,  A. 

Zurich. 
1879      Engelmann,  T.  W. 

Utrecht. 
1879     Frey,  H. 

Zurich. 
1851      Gray,  Asa. 

Cambridge  (Mass.),  U.S. 
1879     Grunow,  A. 

Berndorf,  near  Vienna. 
1870     Hankey,  J. 

Neio  York,  U.S. 
1879      Harting,  P. 

Utrecht. 
1876     Kitton,  F. 

Norwich. 
1879     KoUiker,  A.  v. 

Wiirzbu7-g. 
1879     Leidy,  J. 

Philadelphia,  U.S. 


HONORARY    FELLOWS.  Ixi 


Elected.  I 

1871  I  Maddox,  E.  L. 

London. 
Metschnikoff,  E. 

Odessa. 
Nageli,  C. 

Munich. 
Ny lander,  W. 

Paris. 
Oudemans,  C.  A.  J.  A. 

Amsterdam. 
Pasteur,  L. 

Paris. 
Eanvier,  L. 

Paris. 
Eenard,  A. 

Louvain. 
Sars,  G.  O. 

Christiania. 
Schleiden.  M.  J. 

Wiesbaden. 
Schulze,  F.  E. 

Graz. 
Schwann,  T. 

Liege. 
Schwendener,  S. 

Berlin. 
Smith,  Hamilton  L. 

Geneva  (N.Y.),  U.S. 
Steenstrup,  J.  J.  S. 

Copenhagen. 
Stein,  F.  Eitter  von 

Prague. 
Strasburger,  E. 

Jena. 
Thiimen,  F.  de 

Vienna. 
Tieghem,  Ph.  van 

Paris. 
Wallich,  G.  C. 

London. 
Warming,  E. 

Copenhagen. 
Waterhouse,  G.  E. 

London. 
Weismann,  A. 

Freiburg  i.  Br. 
Woodward,  J.  J. 

Washington  {D.  C),  U.S. 
Zittel,  K.  A. 

Munich. 


Ixii  ROYAL   MICROSCOPICAL   SOCIETY 


SOCIETIES  WHOSE  PRESIDENTS  FOR  THE   TIME  BEIXG  ARE 

EX-OFFICIO    FELLOWS. 

(Elected  1879.) 


UNITED   KINGDOM. 

London — 

Quekett  Microscopical  Club 

Soutli  London  Microscoi)ical  and  Natural  History  Club 

Provinces — 

Birmingham  Natural  History  and  Microscopical  Society 

Brighton  and  Sussex  Natui-al  History  Society 

Bristol  Microscopical  Society 

Bristol  Naturalists'  Society 

(Canterbury.)     East  Kent  Natural  History  Society 

Cardiff  Naturalists'  Society 

Croydon  Microscopical  and  Natural  History  Club 

Eastbourne  Natural  History  Society 

Leeds  Philosophical  and  Literary  Society 

Liverpool,  Literary  and  Philosophical  Society  of 

Liverpool,  Microscopical  Society  of 

(Norwich.)     Norfolk  and  Norwich  Naturalists'  Society 

(Newcastle-upon-Tyne.)       North     of    England    Microscopical 

Society 
Plymouth  Institution  and  Devon  and  Cornwall  Natural  History 

Society 

Scotland — 

Glasgow,  Natural  History  Society  of 

(Perth.)     Cryptogamic  Society  of  Scotland 

(     „     )     Perthshire  Society  of  Natural  Science 

Ireland — 

Dublin  Microscopical  Club 

Belfast  Natural  History  and  Philosophical  Society 


EX-OFFICIO   FELLOWS.  Ixiii 

COLONIES. 

India — 

(Calcutta.)     Asiatic  Society  of  Bengal 

Australasia — 

New  South  Wales,  Linnean  Society  of 

New  South  Wales,  Eoyal  Society  of 

(South  Australia.)     Philosophical  Society  of  Adelaide 

Tasmania,  Royal  Society  of 

Victoria,  Eoyal  Society  of 

Victoria,  Microscopical  Society  of 

(New  Zealand.)     Wellington  Philosophical  Society 

Canada — 
(Halifax.)     Nova  Scotian  Institute  of  Natural  Science 
Montreal,  Natural  History  Society  of 
(Toronto.)     Canadian  Institute 

UNITED    STATES. 

(Boston.)     American  Academy  of  Arts  and  Sciences 
(      „      )     Boston  Society  of  Natural  History 
(Chicago.)     State  Microscopical  Society  of  Illinois 
New  York  Academy  of  Sciences 
New  York  Microscopical  Society 
Philadelphia,  Academy  of  Natural  Sciences  of 
St.  Louis,  Academy  of  Sciences  of 
San  Francisco  Microscopical  Society 
Troy  Scientific  Association 

GERMANY. 

Berlin,  K.  Preussische  Akademie  der  Wissenschaften  zu 

Berlin,  Gesellschaft  Naturforschender  Freunde  in 

(Dresden.)     K.  Leopoldinisch-Carolinische  Deutsche  Akademie 

der  Naturforscher 
(Frankfurt  a.  M.)     Senckenbergische    Natui'forschende  Gesell- 
schaft 
(Frankfurt  a.  M.)     Deutsche  Malakozoologische  Gesellschaft 
Gottingen,  K.  Gesellschaft  der  Wissenschaften  zu 
Jenaische  Gesellschaft  fiir  Medicin  und  Naturwissenschaft 
(Leipzig.)     K.  Sachsische  Gesellschaft  der  Wissenschaften 
(Miinchen.)     K.  Bayerische  Akademie  der  Wissenschaften 

AUSTRIA-HUNGARY. 

(Vienna.)     K.  Akademie  der  Wissenschaften 
(      „      )     K.K.  Zoologisch-botanische  Gesellschaft  in  Wien 
(Prag.)     K.  Bohmische  Gesellschaft  der  Wissenschaften 
(Budapest.)     Hungarian  Academy 

HOLLAND. 

(Amsterdam.)     K.  Akademie  van  Wetenschappen 
Haarlem,    Hollandsche    Maatschappij    der    Wetenschappen    te 
(Societe  Hollandaise  des  Sciences  a  Harlem) 


Ixiv  ROYAL    MICEOSCOPICAL    SOCIETY. 

DENMARK. 

(Kjobenhavu.)     K.  Dauste  Videnskabernes  Selskab 

SWEDEN. 

(Stockholm.)     K.  Svenska  Vetenskaps  Akademien 

RUSSIA. 

Moscou,  Societe  Imperiale  des  Naturalistes  de 

(Odessa.)     Societe  des  Naturalistes  de  la  Nouvelle  Kussie 

St,  Petersbourg,  Academic  Iioperiale  des  Sciences  de 

SWITZERLAND. 

Basel,  Naturforschende  Gesellschaft  in 
Geneve,  Societe  de  Physique  et  d'Histoire  Naturelle  de 
(I^ausanne.)     Societe  Vaudoise  des  Sciences  Naturelles 
(Zurich.)       Allgemeine    Schweizerische    Gesellschaft    fiir    die 

Gesammten   Naturwissenschaften  (Societe   Helvetique   des 

Sciences  Naturelles) 

PRANCE. 

(Amiens.)     Societe  Linneenne  du  Nord  de  la  France 

Bordeaux,  Societe  des  Sciences  Physiques  et  Naturelles  de 

Lyons,  Societe  Linneenne  de 

Marseille,  Academic  des  Sciences,  Belles-Lettres  et  Arts  de 

Montpellier,  Academic  des  Sciences  et  Lettres  de 

(Paris.)     Academic  des  Sciences 

(     „     )     Societe  Botanique  de  France 

(     „     )     Societe  Cryptogamique  de  France 

BELGIUM. 

(Brussels.)     Academic  Eoyale  des  Sciences,  des  Lettres  et  des 

Beaux-Arts  de  Belgique 
(       „       )     Societe  Beige  de  Microscopic 
(        „       )     Societe  Malacologique  de  Belgique 
(       „       )     Societe  Royale  de  Botanique  de  Belgique 

ITALY. 

(Florence).     Societa  Malacologica  Italiana 

Milano,  Istituto  Lombardo  di  Scienze  e  Lettere  di 

(Milano.)     Societa  Crittogamologica  Italiana 

(Pisa.)     Societa  Toscana  di  Scienze  Naturali 

Torino,  R.  Accademia  delle  Scienze  di 

(Vene;«ia.)     E.  Istituto  Veneto  di  Scienze,  Lettere  ed  Arti 

(Roma.)     R.  Accademia  dei  Lincei 

SPAIN. 

(Madrid.)     Sociedad  Esi>ariola  de  Historia  Natural 

PORTUGAL. 

Lisboa,  Academia  Real  das  Sciencias  de 


Vol.  II.  No.  1.]       FEBRUARY,  1879.  [Price  3s. 


Journal 


OF  THE 


Royal 
Microscopical  Society; 


CONTAINING    ITS 


TRANSACTIONS  &  PROCEEDINGS, 


WITH    OTHER 


MICEOSOOPIOAL  AND  BIOLOGIOAL  mFORMATION. 

Edited,  under  the  direction  of  the  Publication  Committee^  by 

FRANK    CRISP,   LL.B.,   B.A.,   F.L.S., 

ONE  OF  THE  SECRETARIES   OF  THE  SOCIETY. 


PUBLISHED    FOR   THE    SOCIETY,    BY 

WILLIAMS   &   NORGATE, 

14,    HENRIETTA    STREET,    COVENT    GARDEN,    LONDON  ; 
AND   20,  SOUTH   FREDERICK   STREET,  EDINBURGH. 


J 


T 


fRIMTBD  BY   WILLIAM   CLOWKS    ANU   SONS,]  [STAMFORD   STRBBT    ANB   CHARING    CROS6. 


JOUENAL 

OV  THB 

EOYAL  MICROSCOPICAL  SOCIETY. 

VOL.  II.    No.  1. 


PAQB 


CONTENTS. 

Tbansactions  of  the  Society — 

I.  On   CEcistks   umbella   and   other   Rotifers.     By  C.  T. 

Hudson,  M.A.,  LL.D.,  V.P.R.M.S.     (Plntes  I.  and  11.)  1 
II.  A  Further  Inquiry  into  the  Limits  of  Microscopic  Vision 
and  the  delusive  application  of  Fraunhofer's  Optical 
Law  of  Vision.     By  Dr.  Roy^ton-Pigott,  M.A.,  F.E.S., 

&c.     (Plate  III.) 9 

III.  On  some  Recent  Forms  of   Camera   Lucida.     By  Frank 

Crisp,  LL.B.,  B.A.,  Sec.  R.M.S.,  &c 21 

IV.  Description  of  a  New  Form  op  Camera  Lucida.     By  J. 

Cunningham  Russell,  M.D.,  Lancaster     ..           ..           ,.  25 

V.  Immersion  Illuminators.     By  J.  Mayall,  jun.,  F.R.M.S.  ,.  27 
VI.  Note   on    a   Revolver   Immersion   Prism   for    Sub-stage 
Illumination.     By   James   Edmunds,   M.D.,   M.E.C.P. 

Lond.,  F.R.M.'^.,  &c 32 

VII.  A   Catoptric   Immersion   Illuminator.      By   John   Ware 

Stephenson,  F.R.A.S.,  Treas.  R.M.S 3o 

VIII.  The  Thallus  of  the  Diatomace.e.     By  F.  Kitton,  Hon. 

F.R.M.S.                 ..           38 

Notes  and  Memoranda             ..          ..          ..          ..          ,.          ..  41 

Sesearches  on  the  Proboscis  of  Butterflies       41 

Contributions  to  our  hnowledge  of  the  Protozoa     42 

Cochineal  for  Staining       43 

•      Prazmowslii's  Heliostat      44 

New  {Auditory^  Sense-organs  in  Insects.    (Plate  IV.) 45 

The  Fibrillae  of  Filifera 49 

The  Ovule 49 

Laboratory  for  Microscopic  Work ..  52 

A  Neio  Micrometer ..  52 

"  Cell-Soul  and  Cellular  Psychology  "     53 

Post-embryonic  Formation  of  Appendages  in  Insects 55 

The  Wehr  Slide 55 

ITie  form  of  the  crystalline  Cones  in  tJie  Arthropod  Eye        '  ..  ^6 

Poison  Glands  of  the  Centipedes       ..      57 

Microbia       58 

Orchella  as  n  Staining  Material       -"'^ 


Vxr.K 

Construction  of  Eye-pieces 59 

Malpighian  Vesseh  of  Insects 60 

Parasitic  Crusiarea 61 

Improvements  in  Micro-photography        62 

Measure  for  Covering  Glass       65 

Origin  of  the  Sexual  Products  in  Hydroids 66 

Sir  Joseph  Hooker  on  the  Modern  Development  of  Micro-botany         ..      ..  67 

Lichens,  Bacteria,  Bacillus  Organisms,  and  the  Lowest  Forms  of  Life       ..  69 

Method  of  representing  an  Object  from  Microscopic  Sections        71 

Microscopy  at  the  Paris  Exhihition          72 

The  Generation  of  Gas  in  the  Protoplasm  of  living  Protozoa     72 

Sperm-formation  in  Spongilla 73 

'I  he  exact   Orientation  of  the  principal  Section  of  Nicols   in  Polarizing 

Apparatus        ••      71 

Improvements  in  Object-glasses         75 

British  A  cari — Oribatidte 76 

Tlie  Structure  of  the  Nerves  in  the  Invertebrata      76 

Development  of  Cephalodia  on  Lichens 78 

Mr.  Soiby's  New  Micro-spectroscope 81 

The  Structure  of  Blood-ves'^ela 82 

Borings  of  a  Sponge  in  Marble         82 

Alcoholic  Fermentation       82 

Dry  Preparations  of  Diatoms,  &o 83 

The  Organs  of  Attachment  of  Stentors      83 

A  new  Method  <f  preparing  a  Dissected  Model  of  an  Insect's  Brain  from 

Microscopic  Sections       S-t 

The  Eelations  of  Ehabdopleura        . .      . .  84 

Formation  of  Ovisacs  in  Copepoda 85 

The  Conidia  of  PoJyporus  suJfureus,  and  their  Development 85 

Polarizer  for  the  Microscope      87 

New  Anthozoa 87 

Parthenogenesis  in  Bees      88 

New  Classification  of  the  Vegetable  Kingdom         90 

TIte  Morphology  of  the  Oxytrichina 91 

The  Sexual  Process  in  Diatoms         93 

Microscopical  Injection  of  Molluscs 94 

Parasitism  amongst  Infusoria 94 

Microscopy  at  the  American  Association  for  the  Advancement  of  Science    ..  95 

Germination  of  the  Spores  of  Volvox  dioicus ^95 

Parasitism  of  a  Coral  on  a  Sponge 9S 

BiBLIOGBAPHY          ,.                ..               ,.                ..               ..               ..               ..               ..  97 

Pkoceedings  of  the  Society    ..          ..          ..           ..          ..           ••  105 


Meetings  of  the  Society. 


1879. 
Wednesday,  February  12. 
„  March  12. 

„  April  9. 

„  May  14. 


1879. 
Wednesday,  June  11. 
„  October  8. 

„  November  12. 

„  December  10. 


HENRY  CROUCH'S 

FIEST-CLASS   MICEOSCOPES 

(JACKSON    MODEL), 

OBJECTIVES,  AND  ACCESSORIES. 


Catalogue,  juU  11  Illustrated,  on  Apjyh'caiion. 

HEITRY  CEOUOH,  66,  Barbican,  London,  E.G. 


-W>'^^^:''>^A'> 


JOUR.  R.MrC.  SOC   VOL, IT.  Pi  I. 


, 


-iv 


- ^-^^ 


''''?^^ 


C  T-  Htuison.  <i£/ . 


CEcistes       ixnabell; 


West  Neu'iiuin  Jr  G  ?  Urfi 


JOUR..  R.  MIC.  Sue.  voL.n.  PI.  n. 


>  '1  f 


.:fe/ 


^^^^Kj^ifk 

■2^^ 

^^SB 

^pri^£ 

'^ij^^w^^^l^^^^B 

I^HJH 

West  New m-xn  i  C?  WtW. 


CorLOcKil-as      volvox. 


JOURNAL 

OF    THE 

ROYAL  MICROSCOPICAL   SOCIETY. 

FEBKUAEY,  1879. 


TEANSACTIONS  OF  THE   SOCIETY. 


I. — On  (Ecistes  umbella  and  other  Botifers. 
By  C.  T.  Hudson,  M.A.,  LL.D.,  V.P.E.M.S. 

(Read  11th  December,  1878.) 
Plates  I.  and  II. 

This  remarkable  new  species  was  discovered  by  Mr.  F.  Oxley 
last  June  in  a  pond  at  Snaresbrook.  Mr.  Oxley  was  so  kind 
as  to  send  me  several  specimens,  but  I  was  unfortunately  pre- 
vented from  giving  them  all  the  attention  they  so  well  deserved  ; 
and  though  I  made  some  sketches  of  this  (Ecistes,  I  was  unable  to 
investigate  its  structure  and  habits  in  the  way  that  I  should  have 
wished  to  do. 

It  is  a  large  handsome  species,  and  the  specimens  sent  to  me 
had  made  their  clay-coloured  fluffy  homes  on  the  leaves  and  in 
the  axils  of  a  sphagnum.  The  tubes,  if  I  may  call  such  loose 
structures  by  so  precise  a  name,  resemble  those  of  the  rotifer  I 
described  as  Melicerta  tyro ;   but  which  I  think  had  better  be 


EXPLANATION  OF  THE  PLATES. 

Plate  I. 

(Ecistes  umbella. 
Fig.  1. — A  group  of  three. 
„     2. — Disk  of  (E.  umbella. 
„     3. — Disk  of  (E.  crystalUnus. 

Plate  II. 

Conochilus  volvox. 
Fig.  1. — A  cluster. 

2. — An  individual,    a,  spermatozoa  on  ovary ;  b,  extremity  of  anus. 

3. — Spermatozoa  (two  forms). 

4. — Extremity  of  anus. 

5. — "Winter  egg  in  ovary  (various  stages). 

6. — Winter  egg  (final  stage). 

7. — Male  in  egg. 

8.— Eye. 
VOL.    II.  B 


2  Transactions  of  the  Society. 

named  Melicerta  tubicolaria ;  as  I  have  now  little  doubt,  in  spite 
of  the  errors  in  his  figures  and  description,  that  this  was  the  rotifer 
out  of  which  Ehrenberg  framed  his  genus  Tubicolaria. 

Nothing  can  be  more  irregular  than  the  shapes  of  the  homes 
in  which  these  creatures  dwell.  They  are  fluffy  masses  of  a 
substance  secreted  by  the  animal  itself,  and  fortified  by  random 
gatherings  of  material  thrown  down  on  them  by  the  action  of  the 
ciliary  disk.  Like  those  of  all  the  tube-making  rotifers,  they  have 
only  a  small  cylindrical  passage  down  their  centre,  up  and  down 
which  the  animal  moves,  and  the  material  of  which  they  are  com- 
posed is  continuous  from  the  rotifer  right  out  to  the  surface.  By 
transmitted  light  they  appear  to  be  hollow ;  but  this  is  not  the 
case,  and  the  dark-field  illumination  will  generally  enable  the 
observer  to  trace  the  delicate  material  everywhere  from  the  outer 
surface  to  the  animal  within.  In  Floscularia  camjpanulata  I  have 
seen  the  young  newly-hatched  male  bore  his  way  with  his  long 
cilia  from  the  side  of  his  mother  right  out  of  her  case  ;  and  I  have 
also  seen  it  die  in  the  attempt.  The  most  remarkable  thing  about 
(Ecistes  umhella  is  its  disk,  which  is  so  strengthened  by  ribs  across 
it  in  various  directions,  that  it  looks  somewhat  like  an  odd  kind  of 
umbrella.  Two  of  these  thickenings  are  very  broad,  and  run 
across,  as  shown  in  the  figure,  from  the  ventral  to  the  dorsal  side  of 
the  disk.  When  the  rotifer  closes  its  disk,  it  naturally  folds  it  so 
as  to  bring  these  stouter  portions  together,  the  thinner  parts  being 
folded  within  them;  and,  in  consequence,  it  often  has  an  odd 
square  look  about  its  head,  that  I  have  never  seen  in  any  other 
species  of  OEcistes.  But  this  strengthening  of  the  disk  is  not 
peculiar  to  it.  The  common  (Ecistes  crijstallinus  has  precisely  the 
same  thing,  only  on  a  much  smaller  scale  (as  may  be  seen  in  the 
Plate,  Fig.  3),  and  similar  thickenings  are  visible  in  CE.  pilula. 

In  (E.  umhella  there  is  on  either  side  of  the  disk  a  branched 
rib  like  a  gusset;  but  the  whole  structure  must  be  viewed  in 
various  directions  and  by  different  modes  of  illumination  to  get  a 
clear  idea  of  it.  The  central  ribs,  when  the  disk  is  viewed  edge- 
ways, are  clearly  seen  to  project  above  its  surface  a  little. 

My  friend  Mr.  A.  W.  Wills  found  this  rotifer  in  one  of  the 
ponds  of  Sutton  Park,  and  exhibited  some  specimens  in  October  at 
a  meeting  of  the  Birmingham  Natural  History  Society.  Mr. 
Wills  has  figured  and  described  it  in  the  December  number  of  the 
'  Midland  Naturalist,'  adding  to  his  interesting  remarks  some  accurate 
measurements  of  a  full-grown  individual.  From  these  it  will  be 
seen  that  CE.  umhella  is  much  larger  than  (E.  crystallinus,  and 
about  twice  as  large  as  (E.  pilula.  On  a  piece  of  alga  which 
Mr.  Wills  has  just  sent  me,  the  two  species  can  be  seen  side  by 
side,  and  form  a  very  pretty  picture.  They  have  been  living  in 
Mr.  Wills'  tank,  and  have  come  to  me  in  excellent  condition  in 


On  (Ecistes  umheUa  and  other  Rotifers.     By  C.  T.  Hudson.     3 

spite  of  the  severe  weather,  which  seems  to  have  killed  all  their 
brethren  in  the  ponds. 

(E.  umheUa  has  two  well-marked  red  eyes  which  can  be  seen  on 
looking  down  through  the  disk ;  they  are  situated  well  within  the 
animal,  below  the  disk,  and  towards  the  dorsal  side,  that  is,  towards 
the  side  where  the  mouth  is  not. 

Ehrenberg's  family,  CEcistina,  ought  of  course  to  be  included  in 
the  family  of  the  Melicertans,  but  I  agree  with  Mr.  Wills  that  the 
genus  CEcistes  ought  to  be  retained,  as  we  have  now  no  less  than 
five  species ;  viz.  (E.  crystaUinus ;  Mr.  Davis'  new  pair,  CE.  inter- 
medius  and  Gi.  hngicornis ;  Mr.  Tatem's  CE.  jjilula ;  and  Mr. 
Oxley's  (E.  umheUa. 

Conochihis  volvox. — I  had  the  pleasure  of  reading  Mr.  Davis' 
excellent  paper  on  this  most  curious  rotifer,*  just  after  I  had 
been  drawing  it  from  a  few  specimens  which  had  survived  the 
transit  from  London  to  CHfton.  The  creature  is  a  bad  traveller, 
not  a  single  sphere  remained  unbroken  ;  and  indeed  the  tube  con- 
tained no  group  with  more  than  four  rotifers  in  the  cluster.  In 
some  respects  this  was  an  advantage,  as  it  enabled  me  to  see  much 
more  clearly  than  I  otherwise  should  have  done  the  animal's 
structure.  First  let  me  say  that  Mr.  Davis'  account  of  this  rotifer 
is  most  accurate.  He  is  quite  right  in  pointing  out  that  there 
are  the  usual  pair  of  setae-bearing  antennee,  one  on  either  side  of 
the  mouth,  not  four  conical  papillae,  each  with  a  bristle,  as  Ehren- 
berg  asserts.  He  correctly  states  that  the  line  of  cilia  is  inter- 
rupted in  one  part  of  the  disk,  and  that  the  notch  in  tie  cilia  is  not 
where  the  mouth  is.  Mr.  l)avis  has  also  most  clearly  shown  the 
peculiarity  of  this  rotifer's  structure  in  having  its  mouth  and  anal 
aperture  on  the  same  side :  and  in  its  fringe  of  large  cilia  enclosing 
that  of  the  small  cilia  as  well  as  the  mouth ;  instead  of  its  being 
enclosed  by  the  smaller  cilia,  and  of  the  mouth's  lying  between  the 
two  fringes.  Mr.  F.  A.  Bedwell  has  given  an  admirable  and  most 
forcible  illustration  of  the  difference  between  the  trochal  disk  of 
Conochihis  and  that  of  Melicerta  in  his  capital  paper  on  the  build- 
ing apparatus  of  Melicerta  ring/ens. 

The  arrangement  of  the  parts  is  so  curious  in  Conochihis,  and 
so  exasperating  to  a  classifier,  that  I  may  venture  to  suggest  even 
a  third  way  of  considering  them.  If  a  crochet  hook  were  supposed 
to  be  pushed  through  the  centre  of  the  disk,  down  the  middle  line 
of  the  body,  and  hooked  on  to  the  end  of  the  foot,  then  on  draw- 
ing the  hook  right  back  again,  the  animal  would  be  turned  inside  out 
like  the  inverted  finger  of  a  glove,  and  be  pulled  through  its  own 
disk  ;  and  the  relative  position  of  its  organs  would  be  nearly  that  of 
an  ordinary  Melicertan.  In  the  drawing  that  I  have  given  of  a 
Conochilus,  it  will  be  seen  that  the  anal  aperture  lies  remarkably 

*  '  M.  M.  J.,'  vol.  xvi.  p.  1. 

B    2 


4  Transactions  of  the  Society. 

high  on  the  back,  and  that  it  has  a  curious  trefoil  opening.  In 
one  of  the  specimens  I  could  distinctly  see  several  spermatozoa 
attached  to  the  ovary  and  still  moving.  The  spermatozoa  were  of 
two  shapes — or  at  all  events  along  with  the  usual  spindle-like  forma 
were  others  like  a  curved  cord  with  a  puckered  ribbon  sewn  all 
down  it.  Both  these  forms  can  be  readily  seen  in  the  sperm  sacs 
of  the  males,  and  both  are  constantly  in  motion.  How  the  sper- 
matozoa got  outside  of  the  ovary  I  cannot  imagine — and  that  some 
were  outside  I  am  certain.  The  ovary,  I  believe,  opens  into  the 
anus,  and  I  know  of  no  way  in  which  the  spermatozoa  could 
escape  into  the  perivisceral  cavity. 

There  is  a  point  of  resemblance  between  Conochihis  and  the 
Floscules  which  is  well  worth  notice.  From  the  mastax  to  the 
mouth  the  alimentary  canal  is  strengthened  in  an  unusual  way  by 
a  tube  much  harder  than  the  surrounding  parts.  In  Floscularia 
campanulata  the  tube  hangs  down  from  the  mouth,  and  is  con- 
stantly thrown  into  long  slow  undulations.  As  it  is  transparent, 
its  edges  only  can  be  usually  brought  into  focus,  so  that  it  looks 
like  two  waving  lines  or  like  the  edges  of  two  flat  membranes,  iind 
thus  it  has  been  described.  Under  favourable  circumstances,  how- 
ever, food  or  water  may  be  seen  to  dilate  it  as  it  passes  down,  and 
I  have  repeatedly  seen  this  happen  in  such  a  way  as  to  make  it 
obvious  that  the  structure  is  really  a  tube.  On  crushing  F.  cam- 
panulata or  Conochilus  volvox,  the  tube  will  be  found  to  remain, 
and  even  to  resist  the  action  of  caustic  potash  along  with  the  harder 
portions  of  the  mastax. 

Notommata  aurita. — A  few  months  ago  I  found  this  rotifer  in 
great  abundance  in  a  pond  near  Bath.  The  water  was  swarming 
at  the  same  time  with  free  Vorticellae  of  a  fine  dark  green,  speckled 
with  brown.  The  bottle  that  I  carried  home  with  me  had  a  very 
large  number  of  these  restless  creatures  in  it,  and  I  found  them 
very  much  in  my  way  as  I  was  examining  the  Notommata,  for  they 
constantly  knocked  up  against  the  rotifers,  and  made  them  with- 
draw the  curious  earlike  apjiendages  from  which  they  derive  their 
name,  and  which  I  was  anxious  to  see.  One  thing  puzzled  me 
very  much,  and  that  was  the  rapid  disappearance  of  the  Vorticellae 
from  the  bottle.  The  surface  of  the  water  was  alive  with  them 
when  I  brought  them  home,  and  next  morning  there  were  not  a 
fourth  of  the  number  to  be  seen.  Almost  all  the  Notommata,  too, 
were  useless  for  purposes  of  observation,  for  they  were  gorged  with 
green  food,  so  that  their  stomachs  hid  the  other  organs.  The  exact 
similarity  of  tint  between  the  contents  of  the  Vorticellae  and  the 
stomachs  of  the  Notommata  had  already  struck  my  attention,  when 
I  thought  I  saw  a  rotifer  (unluckily  on  the  opposite  side  of  a  bit  of 
horn-wort)  holding  one  of  the  Vorticellae.  Could  it  be  possible 
that  these  Notommata  could  eat  the  Vorticellae?     I  put  a  large 


On  (Eeistes  umhella  and  other  Rotifers.     By  C.  T.  Hudson.     5 

piece  of  the  weed,  in  whicli  several  specimens  of  both  creatures 
were  entangled,  under  the  Microscope,  and  with  a  low  power 
watched  eagerly  to  see  if  I  could  catch  the  rotifer  in  the  fact. 
After  a  few  minutes'  observation,  I  was  inclined  to  reject  the  idea  as 
absurd. 

The  Yorticellae  rushed  backwards  and  forwards,  knocked  fear- 
lessly against  the  rotifers,  and,  while  evidently  frightening  the 
latter,  took  no  sort  of  pains  to  get  out  of  their  way  ;  in  fact, 
behaved,  as  to  me  they  always  do  seem  to  behave,  just  like  animated 
machines.  As  to  the  slow-swimming  and  still  slower  crawling 
rotifer  catching  one  of  these  swift  rovers,  the  thing  seemed  impossible. 
Under  any  circumstances,  whether  swimming  or  crawling,  whenever 
the  Vorticella  struck  the  Notommata,  the  latter  either  drew  in  his 
wheels,  and  ignominiously  rolled  over  and  over  to  the  bottom,  or  if 
it  were  crawling  on  a  bit  of  the  weed  it  shrunk  back,  and  contracted 
itself  with  every  appearance  of  alarm. 

Still  there  were  two  ugly  facts  unaccounted  for,  viz.  the  dis- 
appearance of  the  Vorticellae,  and  the  appearance  in  the  stomachs 
of  the  Notommata  of  substance  marvellously  like  them.  I  was  just 
going  to  try  to  imprison  a  Notommata  in  a  coil  of  cotton  with  one 
or  two  of  the  Yorticellae,  when  I  noticed  one  of  the  latter  caught  in 
the  angle  between  two  small  stems  of  horn-wort.  A  Notommata, 
too,  was  crawling  along  one  of  the  stems  in  its  usual  slow  fashion. 
There  was  a  chance  that  the  sluggish  creeper  might  get  to  the 
angle  before  the  Vorticella  darted  off  again  on  its  travels.  For- 
tune favoured  me ;  the  Vorticella  kept  waltzing  round  and  round 
in  the  same  spot,  and  the  Notommata  crawled  on  till  it  all  but 
touched  the  Vorticella.  I  hoped  to  see  the  rotifer  quicken  its 
pace,  or  make — I  will  not  say  a  dart,  that  would  be  too  much, 
but  at  all  events  a  lurch  at  its  prey ;  imagine  my  chagrin  when 
I  saw  it  coolly  curl  round  the  stem  and  begin  to  retrace  its  steps, 
actually  freeing  the  Vorticella  from  its  prison  by  brushing  it  with  its 
back  as  it  crawled  back  again.  There  had  not  been  a  thousandth  of 
an  inch  separating  the  rotifer  s  head  from  the  Vorticella,  and  yet, 
in  spite  of  its  two  eyes,  it  had  not  noticed  it.  Again,  I  thought  of 
bringing  in  a  verdict  of  "  not  guilty  " ;  but  another  good  look  at 
dark  green  stomachs  revived  all  my  suspicions,  and  once  more  1 
patiently  waited  till  another  Vorticella,  possibly  the  same,  re- 
peated its  silly  performance  of  getting  into  a  corner  and  dancing 
there  till  some  one  should  set  it  free.  This  time  it  was  freed  only 
too  effectually.  The  Notommata  once  more  crawled  down  to  the 
captive,  "  without  hurry  or  care,"  and  struck  its  nose  (if  I  may 
use  the  expression)  against  the  Vorticella,  just  as  if  it  were  by 
accident.  But  the  instant  it  did  so  it  jerked  up  its  head,  and 
snapped  at  and  seized  its  victim  with  its  sharp  jaws ;  and  in  a 
second  I  saw  the  whole  contents  of  the  Vorticella  pouring  down 


6  Transactions  of  the  Society. 

the  throat  into  the  stomach  of  the  rotifer.  Guilty  ! — and  without 
appeal. 

There  are  a  few  observations  showing  that  the  rotifers  occasion- 
ally use  their  maxillae  as  teeth,  but  only  a  few,  Mr.  Gosse  men- 
tions the  snapping  action  of  those  of  Synchseta  morclax.  Mr.  Slack 
saw  a  Diglena  chase,  seize  with  its  jaws,  and  shake  an  anguillula 
that  had  presumed  to  jostle  it.  I  have  frequently  seen  Hydatina 
senta  protrude  its  maxilte,  and  snatch  at  some  tempting  green 
globule  that  the  cilia  could  not  quite  force  down  the  mouth ;  and 
once  I  saw  a  small  Notommata  deliberately  snijj  the  side  of  the 
cell  of  an  alga,  and  suck  out  its  green  contents.  On  this  occasion 
I  contrived  to  see  the  catching  of  Vorticellae  by  Notommata  several 
times,  and  in  each  case  the  Vorticella  was  seized  by  the  mtifer's 
maxilliB  and  its  contents  so  completely  appropriated  that  it  was 
hardly  possible  to  see  the  delicate  film  that  was  left  after  the  opera- 
tion had  taken  place. 

Meliceria  ringens.  — Mr.  F.  A.  Bed  well  has  given  a  most  in- 
teresting and  suggestive  account  of  the  building  apparatus  of  this 
rotifer,  in  the  November  number  of  the  '  Monthly  Microscopical 
Journal '  for  1877.*  His  description  of  the  various  currents  which 
pass  round  and  through  this  apparatus  is  admirable.  To  one  point 
alone  do  I  feel  inclined  to  take  any  exception,  and  that  is,  to  the 
separation  of  the  particles  into  "  four  deflected  streams  "  by  the  action 
of  a  sensitive  cushion  above  the  mastax.  I  quite  agree  with  Mr. 
Bedwell  that  a  first  selection  among  the  particles  whirled  round 
the  groove  of  the  disk  is  made  by  "  two  knotty  protuberances  set 
symmetrically  one  against  the  other  "  just  at  the  ends  of  the  collect- 
ing groove,  and  directly  opposite  to  the  chin ;  and  that  from  these 
the  main  stream  of  waste  material  is  directed  in  a  great  rush  over 
the  chin.  But  I  think  that  the  very  feeble  currents  which  creej:* 
along  (as  Mr.  Bedwell  has  so  well  described)  under  the  curved 
edges  of  his  "hopper"  admit  at  least  of  another  explanation.  If 
Meliceria  ringens  is  fed  with  carmine,  and  the  chin  and  its  append- 
ages steadily  watched,  it  will  be  seen  that  on  either  side  of  the  swift 
main  stream  which  carries  the  waste  particles  over  the  chin,  runs  a 
feeble  current  between  it  and  (if  I  may  use  the  term)  the  bank ; 
running,  in  fact,  as  already  said,  under  the  curved  edges  of  Mr. 
Bedwell's  "  hopper,"  and  along  what  Mr.  Cubitt  calls  the  "  chases." 
In  these  currents  are  gently  carried  along  such  minute  particles  as 
are  fitted  to  form  the  pellet,  and  they  pass  over  the  two  notches  at 
the  chin  into  the  pellet  cup.  About  these  facts  I  think  there  can 
be  no  doubt.  It  is  the  modus  operandi  only  that  is  in  question. 
It  is  of  course  possible  that  the  sensitive  cushion  described  by  Mr. 
Bedwell  may,  like  a  skilful  batsman,  strike  the  larger  particles  into 
the  centre  of  the  stream,  and  the  smaller  ones  to  the  sides  where 
*  'M.  M.  J./  vol.  xviii.  p.  214. 


On  (Ectstes  umhella  and  other  Rotifers.     By  C.  T.  Hudson.     7 

the  "  chases "  are ;  but  I  am  inclined  to  think  that  the  effects 
witnessed  are  rather  due  to  the  friction  between  the  sides  of  the 
"  hopper  "  and  the  stream  itself.  Anyone  who  has  sat  in  a  boat 
floating  down  a  swift  stream  must  have  noticed  that  light  floating 
particles  on  the  surface  pass  him,  that  they  are  going  at  a  quicker 
rate  than  his  boat  is ;  and  that  anything  like  a  free  buoy,  which  in 
still  water  would  float  upright,  is  in  the  swift  stream  tilted  fortvard 
as  it  floats,  its  submerged  end  as  it  w^ere  dragging  behind  the  free 
top.  All  this  is  clearly  due  to  the  fact  that  the  upper  portions  of 
the  river  are  flowing  faster  than  the  lower,  which  are  hindered  by 
the  friction  of  the  water  against  the  channel  itself.  In  the  same 
way  the  side  portions  of  the  stream  close  to  the  banks  move  per- 
ceptibly slower  than  those  farther  off",  and  very  much  slower  than 
the  centre  of  the  stream.  The  result  is  that  while  the  heavier 
floating  bodies,  owing  to  their  greater  momentum,  generally  escape 
from  the  feebler  currents  if  they  ever  get  into  them,  the  very  light 
particles  (often  pushed  aside  and  towards  the  banks  by  the  heavier 
ones)  are  constantly  caught  and  retained  by  the  gentle  currents  at 
the  side.  I  think  then  that  the  minute  particles  pass  slowly  along 
the  "  chases,"  merely  because  along  the  chases  run  comparatively 
feeble  currents,  owing  to  the  retarding  action  of  the  sides  of  the 
"  hopper,"  and  especially  of  its  curved  edges. 

1  should  be  inclined  to  think  also  that  the  production  of  the 
peculiar  form  of  the  pellet  is  due  to  mechanical  considerations  out 
of  Melicerta's  control.  For  instance,  the  pellet  is  frequently  seen 
to  rotate  in  one  direction  round  its  axis,  and  then  after  a  few 
revolutions  to  rotate  in  the  opposite  direction  round  the  same  axis ; 
and  to  repeat  this  again  and  again  with  great  regularity,  the 
coloured  specks  on  the  pellet  even  enabling  the  observer  to  time 
the  process.  Now  at  first  sight  this  looks  as  if  Melicerta  had 
reversed  the  action  of  its  cilia  in  the  cup  at  its  own  pleasure ;  but  I 
believe  that  there  is  a  simpler  explanation.  The  cilia  wdth  which 
the  cup  is  lined,  suddenly  curving  inwards  in  turn  one  after  another 
— just  as  on  the  trochal  disk — produce  a  vortex  in  one  constant 
direction  so  long  as  the  pellet  is  small  enough  to  lie  clear  of  all 
of  them,  but  when  it  gets  larger  it  hinders  the  action  now  of  one 
portion  of  the  cilia  lining  the  pellet,  now  of  another,  by  getting 
so  close  to  them  as  to  stop  their  blows,  and  then  the  cilia  on  the 
opposite  side  to  the  checked  ones  have  the  advantage  and  produce 
a  current  towards  themselves,  which  not  only  makes  the  pellet 
rotate  round  its  axis  from  the  checked  ones  toivards  themselves, 
but  at  last  draws  it  bodily  over  to  the  side  where  the  cilia  are  free, 
thus  checking  in  their  turn  those  previously  free  and  releasing 
those  previously  checked.  Of  course,  the  rotation  is  at  once  re- 
versed till  the  pellet  is  drawn  back  to  its  old  position,  and  then 
da  cai)o.     That  the  pellet  is  not  truly  spherical  is,  I  think,  mainly 


8  Transactions  of  the  Societij. 

due  to  the  fact  that  it  is  made  in  a  cup  into  which  material  slowly 
trickles  at  the  edge.  The  greater  portion  of  such  material,  when 
the  pellet  has  reached  a  certain  size,  would  be  whirled  on  to  it 
before  reaching  the  bottom  of  the  cup  —  and  the  nearer  any 
portion  of  the  pellet  was  to  the  bottom,  the  less  its  chance  of 
getting  fresh  accretions.  Hence,  in  the  main,  arises  its  subconical 
shape.  Such  a  shape  would  be  readily  thrown  by  the  motions  of 
Melicerta  out  of  its  first  position,  in  which  its  longer  axis  is  at 
right  angles  to  the  lower  portion  of  the  cup,  into  a  new  position  in 
which  that  axis  lies  across  the  cup ;  and  once  in  this  position  it 
would  not  be  very  easy  to  get  out  of  it.  The  action  of  the  cilia  on 
it  in  this  new  position  would  now  obviously  tend  to  make  it  rotate 
round  its  longer  axis,  as  those  cilia  opposite  to  the  extremities  of 
that  axis  would  have  their  action  checked  by  the  pellet  itself. 
Moreover,  the  fresh  material  would  noiv  tend  to  be  mainly  arranged 
round  the  pointed  end,  as  it  would  be  only  those  cilia  which  were  on 
either  side  of  it  that  would  have  perfectly  free  action  ;  those  oppo- 
site the  larger  end  being  constantly  checked  by  the  pellet's  touching 
them.  This  would  finally  lead  to  a  roughly  cylindrical  pellet  of 
the  usual  form. 

But  I  am  afraid  that  I  have  already  j)ursued  the  subject  too  far 
for  the  reader's  patience ;  I  will  only  say,  in  conclusion,  that  I 
heartily  sympathize  with  IMr.  Bed  well's  appreciation  of  the  wonders 
of  this  living  atom.  Whatever  may  be  the  correct  explanation  of 
the  facts  he  so  lucidly  describes  (and  I  am  by  no  means  confident 
that  my  own  is  the  correct  one),  the  facts  themselves  remain  a  per- 
petual source  of  wonder  and  delight  to  all  who,  like  himself,  not 
only  possess  a  Microscope,  but  are  able  to  use  it. 


(     9     ) 

11. — A  Furtlwr  Inquiry  into  the  Limits  of  Microscopic  Visio)i  and 
the  delusive  application  of  Fraunhofer's  Optical  Law  of  Vision. 

No.  IL 
By  Dr.  Koyston-Pigott,  M.A.,  F.E.S.,  &c. 

(Bead  13th  November,  1878.) 

Plate  III. 

The  writer  has  been  more  particularly  led  into  the  present  subject 
by  the  wide-spread  belief  that  the  limit  of  microscopic  vision  has 
been  reached  by  the  resolution  of  Nobert's  lines  drawn  at  the  rate  of 
112,000  per  inch,  which  probably  gives  the  l-2U0,000th  for  the 
diameter  of  the  smallest  line  supposed  to  be  visible.  It  will  not  be 
uninteresting  to  relate  the  history  of  this  belief. 

The  celebrated  Fraunhofer  (as  stated  in  his  Memoir  to  the 
Bavarian  Academy  of  Sciences,  June  14,  1823)  succeeded  in  ruling 
lines  as  close  as  30,000  to  the  Paris  inch,  which  he  found  totally 
invisible  wath  the  Microscope.  He  also  announced  that  if  A,  be  the 
wave-length,  and  the  light  fell  perpendicularly  to  the  surface  of 
the  ruled  glass,  sine  6'"^  would  become  imaginary,  and  therefore  the 
lines  would  produce  no  coloured  spectra ;  and  he  concluded,  says 
Sir  John  Herschel,  "  that  an  object  of  less  linear  magnitude  than  \ 
can  in  consequence  never  be  discerned  by  Microscopes  as  consisting 
of  parts."  * 

The  skilful  optician  Nobert,  believing  in  this  result  obtained  by 
Fraunhofer,  utterly  despaired  that  anyone  would  ever  succeed  in 
descrying  his  finest  lines  on  glass.f 

Now  with  regard  to  this  very  conclusion  of  Fraunhofer,  Sir 
John  Herschel  regards  it  as  "  one  which  would  put  a  natural  limit 
to  the  magnifying  power  of  Microscopes,  but  "  which,"  says  he,  "  we 
cannot  regard  as  following  from  the  premises  "  (sic),  t 

Well,  Dr.  Woodward  first  achieved  the  honour  of  resolving 
these  lines  with  a  Powell  and  Lealand  tV  immersion  in  1869 ;  § 
and  in  consequence  of  the  grave  doubts  expressed  by  their  maker, 
he  wrote  to  Dr.  Barnard,  a  distinguished  mathematician  (Pres. 
Columbia  College),  who  replied  that  "with  an  objective  that  takes 

*  Art.  "  Light,"  '  Eucyc.  Met.,'  p.  490. 

+  Nobert  thus  wrote  to  Dr.  Colonel  Woodward,  U.S.,  dated  Barth,  Feb.  26, 
1869.  He  expressed  his  belief  that  the  resolution  of  the  higlier  bands  is  an 
impossibility  when  light  is  permitted   to   fall  on  closely  ruled  lines.      '•  The 

formula,"  says  he,  "  sin.  x  —  j  (Fraunhofer's),  if  by  \  we  designate  tlie  length 

of  the  undulations,  by  b  the  distance  between  two  lines  of  the  gr.ifing,  and  by  x 
the  aTigle  of  the  refracted  rays,  gives  for  sin.  x  an  impossible  value  when  6  becomes 
less  than  A;"  that  is  to  say,  wIjcu  the  distance  between  two  lines  is  less  than  a 
wave-length,  the  lines  will  bei-omo  invisible. 

X  'Ency.-.  Met.,'  art   "  Light,"  p.  490. 

§  See  'Month.  Mic.  Jour.,'  Dec.  1869,  quoted  by  Dr.  Woodward. 


10 


Transactions  of  the  Society. 


in  a  cone  of  an  angle  of  from  140^  to  175°  it  is  nonsense  to  talk  of 
this  question  as  settled  by  theory.  We  shall  continue  to  see  closer 
Hues  just  in  proportion  as  Microscopes  and  modes  of  illumination 
are  improved."  * 

That  has  long  been  the  firm  opinion  of  the  writer.  In  the  first 
paper  on  the  subject  of  the  limits  of  vision,  he  stated,  "  I  believe 
this  limit  has  not  yet  been  reached;"!  and  farther  on,  p.  181, 
"  With  special  adaptations  to  subdue  or  destroy  the  brilliant  diffrac- 
tions of  too  bright  an  illumination,  many  minute  details  before 
completely  effaced  may  be  brought  into  distinct  revelation."  When 
these  remarks  were  made,  the  microscopical  world  had  been  recently 
favoured  with  the  beautiful  formula  introduced  independently,  I 
believe,  by  Professors  Helmholtz  and  Abbe,  in  which  further  eluci- 
dation of  the  principle  was  given  by  a  new  formula  including  the 
semi-angle  of  aperture  of  the  objective  used.  Applying  these 
similar  results,  1  obtained,  for  mean  rays  of  wave-length,  4-GT82  of 
an  inch  (46,000th  nearly)  the  following  results: — 

A  Table  of  Proportionate  Eesolving  Powers  %  (some  of  the  details 
of  which  were  as  follows) : — 


Full  Aperture 
of  Object-glass. 


179° 
175° 
150° 
120° 

12°  38' 


Troportionate  Eesolving  Power. 


sill,  a  =  9999G  per  inch 
sill,  a  =  99905 
sin.  a  =  96590         „ 
sin.  a  =  86600         „ 
sill,  a  =  11000 


Semi-aperture. 


89J° 

m° 

60° 
G°  19' 


I  hope  to  show  in  the  following  paper  that  however  truly  this 
optical  law  may  be  deduced  from  the  premisses,  it  utterly  fails  for 
minute  dark  lines. 

An  announcement  that  it  is  possible  to  descry  with  microscopic 
apparatus  the  millionth  of  an  inch  would  be  almost  too  startling  to 
believe.  The  human  eye  can  distinguish  a  hair  under  favourable 
conditions  of  light  and  background  subtending  an  angle  of  even 
less  than  a  second.  The  black  line  dividing  close  double  stars,  such 
as  Xt  Ursae  Majoris,  which  are  both  of  the  same  (fourth)  magnitude, 
does  not  subtend  in  the  telescope  with  a  pov?er  of  300  diameters 
many  seconds  of  arc.  Besides  this,  the  Microscope  differs  only  from 
the  telescope  in  the  length  of  its  focus  and  smaller  aperture,  which, 
according  to  received  dogma,  gives  great  advantages  of  vision  to  the 
instrument  with  so  great  an  angular  aperture.  We  cannot  doubt, 
either,  from  the  tales  of  travellers,  that  birds  of  prey  possess  ex- 
ceedingly acute  vision,  by  which  they  can  descry  small  objects  at  a 

*  See  'Month.  Mic.  Jour.,'  Dec.  1869,  quoted  by  Dr.  Woodward, 
t  P.  175,  'M.  M.  Jour.,'  Oct.  1876.  %  P.  181,  ibid. 


Limits  of  Microsco^ie  Vision.     By  Dr.  Roijston-Pigott.      1 1 

great  distance.  I  myself  knew  a  friend  who  could  see  with  the 
naked  eye  Jupiter's  satellites,  and  dot  down  their  position  though 
ignorant  of  astronomy.  If  a  simple  organ  of  sight  can  distinguish 
such  objects  as  subtend  only  a  second  or  two,  it  would  seem  strange 
that  modern  glasses  can  only  show  objects  presenting  many  seconds 
to  the  eye  at  the  last  visual  image  formed  in  the  eye-piece. 

In  the  following  observations  I  shall  endeavour  to  substantiate 
a  fact  apparently  irreconcilable  with  the  results  of  the  now  famous 
formula.* 

In  point  of  fact,  the  opinion  has  now  become  established  both  in 
Europe  and  America,  that  Nobert's  lines  112,000  per  inch  (or  lines 
of  that  size)  are  the  closest  that  can  be  seen ;  and  that  the  law 
enunciated  in  the  footnote  forbids  the  hope  of  farther  advance  in 
minute  definition. 

Now,  considering  the  readiness  with  which  a  fine  horsehair  can 
be  distinguished  against  a  light  cloudy  sky,  as  also  spider  lines  at 
several  feet  distance,  I  determined  to  mount  upon  glass  several  spider 
threads  and  measure  their  diameter  by  means  of  Browning's  spider- 
line  recording  micrometer.  After  many  trials,  I  found  the  smallest 
of  these  measured  l-35000th  in  diameter  (Fig.  4). 

I  measured  them  by  means  of  Powell  and  Lealaud's  magnificent 
|-  dry  lens.  On  this  spider  thread  i  could  perceive  irregularities, 
nodules,  and  marks  ;  but  the  general  thickness  was  remarkably  true. 
Some  others  measured  tg^h^oj  ts^oo-  ^'^^  coarse  agglomerations, 
cord-like,  were  as  thick  as  tine  spun  glass  ^oV^th. 

It  then  occurred  to  me  to  make  a  novel  use  of  the  "  Aerial  Micro- 
meter "  formerly  described  by  me,  consisting  of  the  "  Browning  " 
inverted  beneath  the  sub-stage,  as  also  placed  in  a  reversed  position 
(see  Fig.  3). 

The  law  established  contains  two  remarkable  elements:  the 
kind  of  light,  i.  e.  the  length  of  the  wave,  and  the  aperture  of  the 
objective.  For  blue  light  (wave  \  =  53000  per  inch)  intermediate 
between  blue  and  indigo,  this,  with  an  aperture  of  150",  would  give 


,  nearly  = 


Extreme  limit  of  "1 
vibibility        / 

53000 

~  2  sin.  75° 

53000  X  2  X  -960'  •'        102000 

*  This  is  thus  stated : — 

If  €  represent  the  smallest  interspace  recognizable  between  two  bright  lines  or 
flisks,  on  the  condition  that  the  diffraction  fringe  of  one  does  not  overlap  that  of 
its  neighbour ;  and 

If  X  be  the  length  of  the  wave  of  light  under  consideration,  which  for  mean 
rays  equals  ^-gxr^  of  '^^  ii^^'i !  ^°*i 

If  o  be  the  semi-aperture  of  the  objective, 

-  (when  aperture  =  180-), 

and 

=  l-96590th  (when  aperture  =  150°). 


12  Transactions  of  the  Society. 

So  that  with  the  more  favourable  blue  ray  the  smallest  interval 
visible  among  contiguous  bright  disks  or  lines  is  about  one  hundred 
thousandth  of  an  inch,  and  that  only  with  the  largest  aperture. 
Such  is  the  belief  disseminated. 

About  ten  years  ago  I  requested  Messrs.  Beck  to  make  for  me 
an  "iris  diaphragm"  with  "adapters"  on  each  side.  By  this  inge- 
nious contrivance,  screwed  between  an  objective  and  the  body,  the 
angular  aperture  could  be  instantly  reduced  at  will. 

It  seems,  on  the  face  of  it,  not  a  little  surprising,  considering 
this  famous  optical  law,  that  the  visibility  of  lines  of  great  minute- 
ness is  very  little  afi'ected  by  great  reduction  of  objective  aperture, 
by  means  of  this  instrument,  or  by  using  low- angled  objectives  of 
sufficient  power  and  excellence  of  manufacture.  Apparently  this 
is  another  failure  of  the  celebrated  law,  as  roundly  stated  and 
generally  received. 

It  will  be  convenient  to  explain  here  two  practical  points : — 

A. — The  method  used  in  finding  the  diameter  of  the  spider 

lines  enclosed  within  the  micrometer. 
B. — The  method  employed  in  measuring  the  absolute  reduction 

of  the  object  in  miniature. 

A. — The  Rev.  ]\tr.  Dallinger  has  given  us  his  beautiful  measure- 
ments of  the  flagella  in  monads,  by  drawing  an  equivalent  line  with 
a  very  hard  fine  pencil  on  white  paper,  by  means  of  the  camera 
lucida.  By  this  process  he,  after  a  great  many  observations, 
determined  its  diameter  to  be  less  than  the  two  hundred  thousandth 
of  an  inch. 

The  plan  I  adopted  was  by  finding  divisions  on  glass  placed  in 
the  focus  of  the  eye-piece  which  appeared  perfectly  coincident  in 
diameter  with  the  observed  spider  line;  and  then  substituting  a 
scale  of  a  hundred  thousandth  of  a  metre,  a  most  careful  measure- 
ment was  made  of  the  apparent  size  of  the  diamond  cut.  The 
process  was  much  facilitated  by  altering  the  length  of  the  draw 
tube,  and  changing  the  objective  until  the  most  acceptable  result 
was  arrived  at.  I  am  indebted  to  Mr.  Beck  for  the  use  of  an 
exquisite  scale  of  this  kind,  as  also  for  the  loan  of  ^^th  objectives, 
dry  and  immersion,  which  latter  has  reduced  the  miniature  to  the 
extraordinary  minuteness  and  precision  of  definition,  at  seven 
inches,  of  one  hundred  and  forty  times  less  than  the  object. 

On  examining  spider  threads,  gathered  after  recent  spinning, 
with  Powell  and  Lealand's  best  I  dry,  and  measuring  them  with 
the  spider-line  micrometer  inserted  in  the  body,  I  was  charmed 
with  perceiving  the  characteristic  brilliant  central  band,  due  to  a 
minute  cylindrical  lens  of  great  beauty,  and  perfection  of  definition  : 
and  searching  for  threads  lying  flat  and  in  clcse  contact,  I  ibund 
some  consisted  of   four  cylinders  in  contact,  showing  four  bright 


Limits  of  Microscopic  Vision.     By  Dr.  Royston-Pigott.     13 

bands  running  longitudinally.  Taking  a  pair  of  these,  the  cross 
wires  of  the  micrometer  were  accurately  adjusted  in  the  centre  of 
each  bright  space,  the  result  for  this  order  of  spider  was  (making 
the  power  lOuO)  with  the  micrometer 

10000  =  15000*^  ^*^^y  °'^^^^  (^'^  ^^-  !>• 

Different  spiders  spin  much  thinner  webs,  and  seem  to  unite  several 
according  to  the  tension  required.  Another  fibre  measured  tt^t^tt, 
and  some  are  discoverable  3  jo-outh.     See  Plate  III. 

B. — The  reduction  by  miniature  will  be  readily  understood 
from  diagrams,  shown  Fig.  3.  There  are  two  ways  of  deciding 
the  ratio  of  reduction:  the  one  by  examining  the  size  of  the 
miniature  itself,  the  other  by  finding  the  magnifying  power  of  the 
ajDparatus  used  as  a  Microscope. 

For  this  purpose  it  was  especially  mounted  on  the  arm  of  the 
Microscope  used  to  carry  the  body  (exhibited  to  the  meeting). 

In  these  ways  it  was  found  that : — 

Immersion   -  Powell  and  Lealaud,  miniatured  36-7  times  at  4^  inches. 
—  6.  Gundlach  „  50-17      „       ^      „ 

„  —  R.  and  J.  Beck  „        140  „       7        „ 

The  distance  between  object  and  spider  lines  in  the  focus  of  the 
positive  eye-pieces  varied  accidentally  with  the  length  of  the  objec- 
tive mount  itself.  But  the  "  Beck  glass  "  required  seven  inches  to 
do  it  justice,  and  also  to  get  the  miniature  sutBciently  reduced.  It 
was  easy  to  form  the  image  at  any  desirable  distance,  but  then  the 
mirror  could  not  be  used  very  well  beyond  seven  inches,  nor  the 
micrometer  held  sufficiently  steady  without  complex  arrangements. 
The  one  shown  is  simple  and  adequate. 

The  miniature  can,  it  is  evident,  be  carried  to  any  extent ;  which, 
however,  is  limited  to  certain  dimensions  depending  upon  two  im- 
portant conditions — brilliance  or  darkness.  A  very  brilliant  line  or 
disk  is  enlarged  considerably,  whilst  a  dark  fine  is  little  changed. 

If  you  miniature  the  sun's  disk  by  viewing  an  aerial  imao-e  of 
it  formed  by  a  3-inch  lens  (100"  distant),  employing  a  magnificent 
tV  immersion,  you  will  get  a  disk  reduced  1000  times  theoretically  ; 
and  since  ^^  of  an  inch  is  the  diameter  of  the  image  of  the  sun 
formed  by  the  3-inch  lens,  its  diameter  miniatured  on  the  stage  is 
1000  times  less,  or 

382000  "^  iOOOOO  '^^^^^y- 


See  '  Proc.  Key.  Soc.,'  No.  146,  p.  428. 


14  Transactions  of  the  Society. 

But  in  the  microscope  it  appears  quite  the  ten  thousandth  of 
an  inch,  or  nearly  four  times  larger  than  it  ought  to  be,  if  light  had 
no  undulatory  waves.  And  this  too,  whilst  using  the  most  exquisite 
glasses  obtainable.  This  tremendous  fact  shows  how  hopeless  it  is 
to  expect  brilliant  disks  to  appear  of  the  proper  or  natural  size,  if  I 
may  so  speak,  in  the  microscope. 

In  view  of  the  extraordinary  result  of  the  measurement  of  solar 
spectra  already  alluded  to,  a  very  natural  doubt  will  arise  in  the 
minds  of  those  who  have  not  had  practice  in  this  method  of  minia- 
ture, as  to  the  correct  effect  of  the  glasses.  Now  the  best  process 
for  solving  the  doubt  is  to  watch  the  spider  threads  successively 
reduced  from  ten  to  fifty  times.  The  operator  will  find  it  a  slow 
process,  as  every  possible  adjustment  of  centricity  and  correction  for 
aberration  must  be  carefully  attended  to  the  whole  time,  as  well  as 
arranging  the  light.  It  cost  me  at  first  about  six  hours'  work. 
But  then  the  miniatures  become  so  exquisitely  smaller,  the  work  in 
its  very  novelty  becomes  fascinating,  and  encourages  one  to  per- 
severe. The  observer  will  have  no  chance  of  splendidly  defining  the 
millionth  of  an  inch  unless  he  is  accustomed  to  high-power  mani- 
pulation, and  remembers  that  both  upper  and  lower  objectives  must 
be  both  corrected  by  the  screw  collars  for  uncovered  objects  (dry 
or  immersion),  and  change  of  distance  of  the  focal  images.  Some- 
thing too  should  be  understood  of  the  efiect  of  change  of  "  aperture  " 
upon  the  appearance  of  a  transparent  cylinder  of  spider  silk.  It 
must  be  remembered  that  the  aperture  of  the  miniaturing  objective, 
as  this  is  used  in  an  inverted  position,  is  greatly  reduced  as  regards 
the  incident  pencils  emanating  from  the  spider  lines. 

A  pencil  of  rays  proceeding  from  the  cross  or  intersection  of 
the  spider  lines  about  six  inches  i'rom  the  back  glass,  enters  it  at 
an  aperture  of  a  few  degrees  only,  perhaps  ten.  Now  if  a  cylinder 
of  glass  or  spider  gum  be  viewed  with  a  low-aperture  objective 
(say  H),  it  will  present  two  black  borders,  and  the  breadth  of  these 
borders  narrows  as  the  aperture  is  increased,  and  vice  versa.  Also 
when  the  spider  thread  is  diminished  more  and  more,  these  black 
borders  appear  almost  to  coalesce  until  only  a  black  line  appears. 
The  middle  bright  part  vanishes  with  attenuation. 

Then  it  may  be  further  urged  that  a  very  fine  glass  forms 
miniatures  of  an  object,  theoretically,  by  merely  optically  reversing 
the  rays  as  perfectly,  indeed  more  so,  than  in  the  enlarged  image 
of  the  same  object.  If  therefore  we  can  see  the  minute  sjiider  line 
very  perfectly  magnified  one  thousand  times,  we  can,  a  fortiori,  see 
the  miniature,  which  is  only  fifty  times  smaller,  with  great  precision. 
So  much  for  the  objection  against  the  accuracy  of  miniatures  formed 
by  an  excellently  adjusted  objective. 

But  a  crucial  test  is  suj^'plied  by  observing  sets  of  cross  wires 
separated  a  small  space.    Fortunately  I  had  requested  Mr.  Browning 


Limits  of  Microsc(ypio  Vision.     By  Br.  Boyston-Pigott.      15 

to  put  a  double  set  of  cross  wires,  and  also  a  set  of  parallel  wires, 
in  the  micrometer.  The  head  of  the  instrument  is  divided  into  one 
hundred  parts,  and  a  half  or  quarter  part  is  readily  seen  with  the 
naked  eye.  I  may  here  observe,  when  the  wires  are  reduced 
thirty-eight  times  by  the  |^  (as  one  division  of  the  micrometer  is 
the  roAo  0  of  ail  i^^ch  of  motion  in  the  wires),  a  single  division  for 
the  miniature  then  reckons  ^^o"(Toth.  But  I  found  a  quarter  of  a 
division  made  a  perceptible  difference  in  the  apparent  thickness  of 
two  coincident  webs  ;  whilst  three  ivhole  divisions  separated  the 
webs  so  completely.,  that  a  narrow  strip  of  light  could  be  discerned 
between  them  (not  much  room  here  for  swellmg  or  enlargement  of 
the  lines !). 

I  then  changed  the  glasses,  putting  the  best  glass  in  the  body, 
and  the  older  one  (both  newly  formulated)  in  the  micrometer  :  the 
definition  was  not  so  good.  It  required  3^  divisions  to  separate  the 
same  lines. 

This  dividing  of  close  lines  by  means  of  a  very  finely  con- 
structed micrometer  is  quite  satisfactory  to  my  mind,  and  I  should 
hope  conclusive  as  a  crucial  test  to  others  who  may  witness  it  that 
the  lines  are  very  truly  portrayed. 

The  following  little  circumstance  has  an  interest  of  its  own. 
Having  conveyed  my  instruments  home  from  the  London  Museum, 
S.K.,  I  found  the  webs  entirely  covered  with  London  dust.  Upon 
getting  them,  however,  into  rapid  vibration,  I  succeeded  in  shaking 
off  nearly  the  whole  before  measuring  them.  A  few  minute  particles 
adhere  here  and  there  ;  and  though  these  webs  are  diminished  fifty 
times — i.e.  to  the  300, 000th  of  an  inch — these  particles  .of  dust 
are  visible  on  the  web  in  this  state  of  reduction.  This  result  is  the 
most  surprising  of  all. 

It  was  found  that  under  this  reduction  (fifty  times)  it  required 
five  divisions  to  separate  the  spider  lines,  or  a  movement  of  jo  o^^ 
of  the  micrometer,  i.  e. 

5     _   5   _   1 
50  X  10000  ~  500000  ~  100000  " 

Each  division  represented  here  on  the  micrometer  head 

1 


500000 


of  an  inch 


in  the  field  of  view  of  the  Microscope. 

It  is  interesting  to  inquire  what  effect  separating  the  spider 
lines  has  upon  the  discriminating  power  of  vision.  The  optical 
conditions  of  seeing  a  black  line  upon  a  white  ground,  and  sepa- 
rating or  clearly  dividing  between  two  close  minute  black  lines,  are 
totally  different.  The  researches  of  Dr.  Jurin,  150  years  ago,  and 
of  Dr.  Eobinson,  F.E.S.,  the  astronomer,  on  the  subject,  are  very 
interesting  ;  but  no  observations  have  yet  been  made  of  the  minute- 


16  Transactions  of  the  Society. 

ness  about  to  be  related.  The  question  arose,  Is  it  jDOSsible  to 
estimate  a  bright  space  between  two  spider  hues  when  total  separa- 
tion is  only  the  eight  millionths  of  an  inch,  the  lines  themselves 
being  the  SUOOth  and  the  70U0th  of  an  inch  respectively,  and 
reduced  in  the  miniature  thirty-eight  times  ?  Beducing  the  numbers 
to  decimals,  if  S  be  the  space  reckoned  between  the  centres  of  the 
spider  lines,  it  is  evident  if  t  and  t'  be  the  spider  lines  in  diameters, 
and  X  be  the  required  interval  (see  Fig.  5), 

The  value  of  S  was  found  by  carefully  measuring  the  movement  of 
the  micrometer  =  to t oo ?  which  just  brought  the  bright  separating 
interval  into  view.  Therefore  we  have  the  required  size  of  interval 
(considering  it  diminished  thirty-eight  times), 

3  1111 


38  X  10000       2     38.8000       2     38.7000 

=  0-00000789  -  0-00000164  -  0-00000187 

=  0-00000789 

-  0-00000351 


•00000138 
23W0^^"^'y' 


or  about  half  the  interval  between  the  centres  of  the  wires.* 

The  astounding  sight  of  wires  or  webs  separated  by  an  interval 
of  light  less  than  the  two  hundred  thousandth  of  an  inch  can  only 
be  explained  by  the  light  being  subdued.  Indifferent  glasses  cause 
diffraction  images,  besides  clouding  over  the  view  with  residuary 
spherical  aberration  much  more  difficult  of  cure  than  the  colour. 
Without  this  interval — I  may  say,  this  extraordinary  interval — one 
might  conclude  the  webs  are  in  some  mysterious  manner  enlarged 
in  the  miniature  beyond  the  calculated  value.  And  so  they  are  in 
poor  glasses  ;  for  the  image  appears  blurred — swelled,  as  it  were — 
or  adumbrated.  But  now  the  lovely  precision  of  definition  witnessed 
in  high-class  glasses,  not  only  of  the  webs,  but  of  dust  on  them 
and  specks  on  the  lamp-glass,  precludes  any  suspicion,  in  face  of 
this  interval,  of  the  enlargement  of  the  lines  encroaching  much 
upon  its  dimensions.     Besides  all  this,  as  the  webs  pass  and  repass 

*  Putting  the  decimals  into  fractions, 

_       1  1  J    ,  _       1 


127000'  ^         610000'       ^          532000 

The  abo.ve  calculation,  it  must  be  remembered,  refers  to  the  effect  of  the 

micrometer  screw  diminislied  thirty-«eight  times  by  the  Powell  and  Lealand  \ 
best  immersion. 


Limits  of  Microsco'pic  Vision.     By  I)r.  Royston-Pigott.      17 

each  other,  the  smallest  movement  of  the  screw  changes  their 
apparent  thickness  before  division  or  separation  is  seen. 
The  miniatures  were  measured  as  follows  : — 

At  Distance.  Miniature  reduced. 

Inchps.  Times. 

6|      . .  . .  Very  old  i  Powell  and  Lealand          . .      . .        49 

6 J     ..  ..  1862  i  Powell  and  Lealand  (immersion)  ..       58 

61     ..  ..  1875  A              „              „                „           ..       55 

7       ..  ..  1878  2^  R- and  J.  Beck  (immersion)         ..  140 

7       ..  ..      1878  Jjj  Beck  (dry)      118-6 

6J      ..  .,      1873  ^  Gundlaeh  (immersion) 91-3 

5  J      .,  ..     1877  i  Zeiss  (oil  immersion)       49 

Qh  ..  ..  1S68  1-inch  Powell  and  Lealand        ..      ..  6-07 

6i  ..  ..  1851  1  Andrew  Boss 27-6 

6  ..  ..  1870JWray 13-4 

6  ..  ..  1870  1      „     29-5 

To  accurately  adjust  the  observing  and  miniaturing  objectives 
in  the  same  optical  axis  is  easily  done  with  low  powers.  If  both  are 
equal  in  power,  the  test  of  the  quality  is  very  severe,  as  I  have 
shown  elsewhere.*  With  a  then  excellent  Powell  and  Lealand  \ 
made  for  me  in  1862,  and  improved  by  them  after  its  return  to  the 
makers,  a  fog  is  still  seen  when  observed  by  their  brilliant  newly- 
formulated  \  immersion.  But  still  the  spider  lines  are  visible.  It  is 
not  till  objectives  of  equal  and  I  may  say  of  surpassing  beauty  of  defi- 
nition are  opposed  to  one  another  above  and  below,  nose  to  nose,  that 
their  exquisite  powers  of  displaying  fine  black  details  are  exhibited. 

The  Gundlach  immersion  is  of  very  fine  quality.  On  reference 
to  the  table,  it  diminished  the  spider  lines  91 '3  times  when  the 
distance  between  them  and  the  miniature  was  6^  inches.  This 
gave  for  the  first  and  second  lines  (soW  and  yoVoth  diameter 
respectively)  miniature  sizes  of 

^^*^^^ 73^°^"°^^'^'- 

2°^^*^^ 64^  " 

The  sizes  of  the  web  No.  1  with  the  difierent  objectives  may 
thus  be  tabulated  : — 

Dist.    Inches  focus. 
6i-  1  i  Ross        A  Powell        \  Powell  and  Lealand        -Jjj  Beck 

1  1  1  1  1 

48000    220000    300U00         460000         1120000 

These  were  mostly  at  6^  or  Q^  inches.  At  a  greater  distance 
— 10  inches — the  diameters  of  the  spider  hne  of  ^oVtt  with  the  two 
latter  glasses  would  be, 

i  Powell  and  Lealand  -^^  Beck 

1  1 

640000  1600000 

*  '  Phil.  Transact.,'  vol.  ii.,  1871. 
VOL.  II.  •  C 


18  Transactions  of  the  Society. 

These  astonisliing  results,  so  contrary  to  what  had  been  gene- 
rally supposed,  demand  thorough  investigation.  And  with  a  view 
to  elucidate  this  unusually  important  subject,  it  will  be  interesting 
to  inquire  what  is  the  visual  angle  of  fine-line  objects  just  visible 
by  different  observers. 


Diimeter 

Distance 

Anglo. 

of  Hair. 

visible. 

feet 

seconds. 

Mr.  Broun,  F.R  S.,  '  Proc.  Roy.  Soc'   .. 

•0026 

36 

H 

Mr.  Slack,  P.R  MS 

•003 

m 

1 

Witli    sun    illumination   and   grey  sky^ 
Background J 

■003 

76 

6-lOth.s 

Against  white  wall  of  house,  sun  still) 
shining j 

•003 

113 

4-lOths 

Lit  up  by  sun  glittering         

•003 

173* 

It  is  now  requisite  to  determine  what  would  be  the  visual  angle 
of  the  spider  line  iroVo  of  an  inch  miniatured  140  times  smaller 
with  the  Beck  4o,  and  then  magnified  up  1000  times  by  an  eighth 
immersion  with  C  eye-piece  and  about  10  inches  of  tube.     Here 

Visual  diameter  of  web  S  =  — -—  -¥  140  x  1000  at  a  distance  of  10  iuches. 

oOOu 

Hence 

Pern.         5  1000  1 

''''■ '  =  Rl^dhTs  ==  To  =  iTu-iaoooiao  =  moo  =  ^'  ''''""^'  ^^"■^^- 

The  most  ready  w^ay  of  getting  the  value  of  the  fraction  in 
seconds  is  by  recollecting  that  60"  =  ^4^^  nearly. 

deferring  now  to  the  former  table,  it  will  be  found  by  simple 
arithmetic  that  since  the  Beck  oV  immersion  shows  theoretically  a 
visual  angle  of  18  seconds,  miniaturing  140  times,  a  glass  reducing 
only  fifty-eight  times  ought  to  show  at  an  angle  of  7 J  seconds  at  a 
power  of  1000,  and  at  a  power  of  500  at  about  4  seconds.  I  see 
the  line  plainly,  most  charmingly  defined  with  500,  and  can  even 
see  them  when  miniatured  only  thirty  times.  A  good  deal  might  be 
written  on  this  extraordinary  fact.  As  the  aperture  of  the  objec- 
tives is  diminished  the  spider  lines  look  blacker,  and  therefore 
larger,'    I  reserve  this  question  for  future  treatment. 

In  inferior  glasses  the  spider  lines  are  thickened,  and,  besides 
this,  garnished  with  secondary  lines,  true  diffraction  lines,  and  this 
you  may  see.  I  first  detailed  the  metliod  of  miniatures  in  the 
'  Philosophical  Transactions  '  eight  years  ago ;  but  I  have  had 
nearly  twelve  years'  experience  of  this  method,  and  I  have  several 
times  recommended  it  to  the  microscopical  world  with  great  cor- 
*  The  glittering  line  here  would  afford  a  broad  spurious  line  greatly  enlarged. 


Liinifs  of  Microscopic  Vision.     By  Dr.  Roxjston-Pigott.     19 

diality.  It  is  superior  to  all  others  for  detecting  residuary  errors, 
and  when  these  are  nearly  compensated  the  miniatures  of  spider 
lines  of  any  size  are  portrayed  with  enchanting  precision. 

To  sum  up : — The  whole  question  of  minute  vision  is  the  least 
visual  angle  first  of  naked  vision,  and  secondly  in  instrumental 
vision. 

It  can  hardly  be  expected  that  any  Microscope,  especially  if 
connected  with  miniature  apparatus,  involving  the  total  use  of 
some  twenty  lenses  arranged  as  nearly  as  possible  with  one  conti- 
nuous optical  axis, —  that  any  iMicroscope,  I  say,  can  ever  equal  the 
simplicity  of  human  vision.  But  then,  with  the  unassisted  sight 
we  can  easily  determine  the  limits  of  vision  by  receding  from  the 
object,  and  so  making  the  visual  angle  smaller  and  smaller  until  the 
hair  vanishes.     This  we  may  call  the  vanishing  angle  6. 

Now  the  art,  if  I  may  so  speak,  of  making  very  minute  objects 
visible,  may  be  applied  by  my  method  to  render  them  distinctly 
visible  as  they  get  smaller  and  smaller  as  miniatures,  and  at  last 
reach  the  vanishing  limit. 

But  to  my  eye,  which  is,  I  must  confess,  the  worse  for  these 
experiments,  hues  can  be  formed  under  the  Microscope  which  also 
by  lowering  the  ocular  power,  or  diminishing  the  miniature, 
resemble  (I  will  not  say  absolutely  identify  themselves  with)  the 
vanishing  phenomena  of  naked  vision. 

When  I  see  spider  lines  sharply  defined  become  beautifully  less, 
and  give  one  the  same  appearance  as  a  hair  upon  a  window-pane, 
vanishing  as  its  visual  angle  reaches  the  limit,  I  am  bound  to 
believe,  nay  be  assured,  though  against  all  modern  belief  and  theory 
apparently,  that  I  do  see  these  exquisitely  small  lines  just  on  the 
point  of  evanishment  at  a  very  small  visual  angle  indeed.  Anyone 
with  ordinary  sight  can  see  a  human  hair  on  a  window-pane 
against  a  moderately  white  sky  at  a  distance  of  two  feet  and  a 
quarter.     This  is  an  angle  of  20  seconds. 

At  five  feet  it  is Nine  seconds. 

„    ten  feet  it  is     Four  and  a  half  seconds. 

„    twenty  feet  it  is       ,.      ..     Two  and  a  quarter  seconds. 

Now,  on  comparison  of  the  minute  lines  exhibited  by  me 
microscopically,  the  hair  lines  appear  equally  small  in  each  mode, 
either  by  viewing  them  on  a  window-pane  at  a  yard  off,  or  in  the 
microscope  diminished  fifty  times,  and  then  sufliciently  enlarged. 
The  irresistible  conclusion  from  this  comparison  is  that  the  eye  can 
discover  a  minute  hair  line  either  on  the  window-pane  or  in  the 
apparatus  exhibited,  at  certainly  a  smaller  angle  than  20  seconds. 
In  other  words,  the  minute  microscopic  image  appears  as  small  as 
a  hair  several  feet  off,  according  to  the  acuteness  of  vision. 

The  highest  experimental  proof  by  comparison  is  thus  strongly 
in  favour  of    a   line  sharply  and  clearly   defined,  subtending  an 

c  2 


20  Transactions  of  the  Society. 

angle  of  20  SGconds,  and  probably  a  good  deal  less,  as  2  seconds 
is  the  visual  limit  that  can  be  seen  in  the  apparatus  or  by  the  eye 
alone. 

Another  very  curious  point  is  worth  mentioning.  Dr.  Jurin 
150  years  ago  stuck  two  pins  on  a  window-pane,  and  found  that 
v/hen  placed  near  each  other  he  could  not  divide  them  except  when 
the  interval  between  them  reached  the  wide  visual  angle  of  30". 
But  when  only  one  pin  was  viewed,  he  could  distinguish  it  at  a 
visual  angle  of  from  ^  to  3  seconds  ! 

This  interesting  fact  explains  what  I  have  witnessed  in  sepa- 
rating the  spider  lines  of  the  micrometer  in  these  miniatures :  the 
interval  could  only  be  seen  when  the  lines  were  separated,  centre  to 
centre,  three  divisions  (micrometer),  each  division  rejjresenting 
-^^^ —  when  a  minuendo  oi  fifty  times  was  employed  ;  yet  one  can 
see  a  most  sensible  thickening  of  the  gossamers  just  beginning  to 
separate  by  moving  the  micrometer  half  a  division.  From  this,  I 
presume,  a  similar  phenomenon  was  produced,  though  very  much 
less  pronounced  than  Jurin's  case.  It  is  marvellous  to  me  that  a 
visible  bright  space  between  these  lines  can  be  seen  at  all  when 
their  centres  are  sejiarated  only  three  divisions,  i.  e.  ^  ^  ^  'j^  ^  ^  ^  or 
— ^ —  of  an  inch.      Considering  that  there  must  be  some  resi- 

3  0  0  0  0  0  .  ^ 

duary  aberration,  however  small,  and  that  the  error  of  each  set  of 
glasses  accumulates  in  the  final  image  presented  to  the  eye,  it  seems 
to  me  wonderful  that,  notwithstanding  Jurin's  fact,  a  division  is 
visible  between  the  gossamers  at  all  with  so  light  a  movement  as 
described. 

In  continuation  of  this  subject,  I  propose  to  offer  to  the  Society 
some  researches  on  the  efiect  of  large  and  small  apertures  in  object- 
glasses.  I  beg  to  commend  this  research  to  the  earnest  attention 
of  the  rising  generation  of  microscopists.  Unless  I  am  very  much 
mistaken,  the  idea  propagated  in  reference  to  the  limits  of  micro- 
scopic vision  is  totally  erroneous ;  whilst  for  brilliant  lines  or 
minute  disks  of  great  brilliance,  I  have  not  the  slightest  hesita- 
tion in  embracing  the  truths  conveyed  in  the  exquisite  formula 
presented  to  the  microscopical  world  by,  I  believe,  independently, 
Professors  Helmholtz  and  Abbe. 

It  is  almost  needless  to  remark  that  very  firm  supports  and 
delicacy  of  the  adjustments  as  regards  spherical  aberration  and 
illumination  are  essential  to  the  success  of  this  refined  kind  of 
definition. 


(     21     ) 


III. —  On  some  Recent  Forms  of  Camera  Lucida. 

By  Frank  Crisp,  LL.B.,  B.A..  Sec.  R.M.S.,  &c. 

CBead  Uth  December,  1878.) 

During  the  present  year  four  or  five  forms  of  camera  lucida  have 
been  brought  forward,  all  claiming  to  be  original,  and  to  enable  the 
observer  to  see  more  readily  the  image  of  the  object  and  the  point  of 
the  pencil  at  the  same  time,  and  I  have  thought  it  might  be  in  some 
degree  desirable  to  notice  them — as  a  matter  of  history,  at  any  rate. 

(1)  The  first  is  that  of  Dr.  Hofmann,  the  well-known  optician, 
of  Paris. 

Fig.  1  shows  the  camera,  properly  so  called,  and  Fig.  2  its 
transverse  section. 

The  rays  coming  from  the  object,  and  passing  through  the  lens 
C,  meet  the  plate  of  silvered  glass  A,  by  which  they  are  reflected 
to  the  transparent  glass  plate  B,  and  thence  to  the  eye  through  the 


Fig.  2  {,  V 


aperture  at  E.  At  D  are  two  lenses  of  different  foci,  which  can  be 
interposed  between  the  eye  and  the  paper,  as  with  the  ordinary 
Wollaston  form. 

With  a  vertical  Microscope  the  additional  piece  of  apparatus 


22  Transactions  of  the  Society. 

(Fig.  '6),  containing  a  reflector  at  N,  is  employed,  the  camera  fitting 
over  it  at  Gr,  and  the  whole  being  inserted  into  the  tube  of  the 
Microscope  by  the  part  H. 

The  instrument  is  thus  suitable  for  powers  up  to  500 ;  beyond 
this  limit,  however,  it  is  desirable  to  substitute  for  the  colourless 
glass  plate  B  a  tinted  one. 

The  camera,  to  use  Dr.  Hofmann's  expression,  "  suppresses  all 
existing  eye-pieces,"  but  with  objects  requiring  only  small  mag- 
nification to  be  within  the  field  of  the  camera  the  arrangement  is 
employed  which  is  shown  in  Fig.  4.  It  consists  of  two  plano- 
convex lenses  of  difierent  foci,  and  slides  into  H. 

The  part  No.  2  may  be  used  alone.  No.  3  being  taken  away. 
If  the  image  of  the  object  is  still  beyond  the  field  of  the  instrument, 
the  lens  in  No.  2  is  unscrewed,  and  No.  3  replaced,  which  gives  a 
second  amplification ;  and  with  both  lenses  in  their  place  a  third 
is  obtained. 

Dr.  Hofmann  writes  that  this  apiiaratus  is  the  result  of  an 
exjoenditure  of  no  little  time  and  thought  on  his  part,  and  that  it 
has  been  very  highly  commended  by  leading  men  on  the  Continent. 

(2)  A  second  form  also  originates  in  France,  and  is  the  invention 
of  M.  Pellerin,  who  describes  its  principle  in  the  '  Comptes  Kendus '  * 
of  the  French  Academy. 

With  the  view,  as  he  expresses  it,  of  avoiding  the  weakening  of 
one  of  the  images  through  reflection  by  a  transparent  plate  as  in  some 
forms,  and  the  irksomeness  of  others  which  require  that  the  object  and 
the  drawing  should  each  be  viewed  with  half  the  pupil,  he  suggests 
the  following  arrangement,  which  is  an  imitation  of  M.  Cornu's 
polarizer,  and  gives  two  images  of  the  same  intensity  and  visible  at 
the  same  time  by  the  whole  of  the  pupil. 

A  Wollaston  camera  lucida  being  made  of  glass  having  an  index 
higher  than  the  extraordinary  index  of  spar,  there  are  joined  to  the 
face  which  has  an  angle  of  135°  a  plate  of  spar  and  a  prism  made 
of  the  same  material  as  the  camera,  having  its  second  face  parallel 
to  the  face  whence  the  rays  emerge.  Thus,  at  a  suitable  inclination, 
one-half  the  light  coming  from  the  object  will  be  totally  reflected  as 
extraordinary  rays,  and  a  part  of  the  light  coming  from  the  drawing 
will  be  transmitted  as  ordinary  rays.  The  portions  reflected  and 
transmitted  will  be  each  one-half  if  there  is  no  reflection  of  the 
ordinary  rays,  the  condition  for  which  is,  that  the  glass  of  the  two 
prisms  and  the  cement  which  unites  the  pieces  shall  have  the  ordi- 
nary index,  and  in  practice  this  can  always  be  approximately 
attained. 

For  these  assumed  conditions,  and  the  plate  of  spar  being  per- 
pendicular to  its  axis,  the  following  calculation  is  given  of  the  field, 
which  is  then  equal  in  all  directions :  in  the  interior  of  the  glass 

Vol.  Ixxxvi.  p.  764. 


Some  Recent  Forms  of  Camera  Lucicla.     By  Frank  Crisp.    23 

the  extreme  rays  make  an  angle  x  the  complement  of  the  limiting 

angle, 

lie  n     ry 

COS.  X  =  ^  ,         X  =  2G  ; 

but  that  the  faces  of  entrance  and  emergence  may  be  cut  perpen- 
dicularly to  the  mean  direction  of  the  rays,  the  angle  of  refraction 

of  the  extreme  rays  is  ^  and  the  angle  of  incidence  y,  so  that 


sm.  y  =  «o  sin.  - » 

sm.,-^           2 
y  =  22^. 

n^ 

The  field  (maximum  in  these  conditions)  is  4i° ;  the  instrument 
will  take  this  in  completely  ^Yithout  rotation  if  the  face  attached  to 
the  spar  is  the  third  of  the  other,  the  aperture  for  the  eye  being 
near  its  edge.     The  angle  adjacent  to  the  sjDar  is  90°  —  13'^  =  77°. 

To  regulate  the  intensity  of  the  two  images,  a  polarizer  may 
be  interposed  in  the  path  of  the  most  luminous  rays,  such  an 
apparatus,  for  example,  as  M,  Cornu's  made  of  the  materials  above 
mentioned. 

No  drawing  accompanies  M.  Pellerin's  paper.  He  adds  that  a 
camera  lucida  of  the  same  description  may  be  made  for  vertical 
Microscopes  by  replacing  the  quadrangular  prism  by  a  parallelo- 
piped  with  an  angle  of  77°. 

(3)  The  third  arrangement  is  that  of  Mr.  James  Swift,  shown 
in  Fig,  5,  and  can  be  used  at  any  inclination  of  the  Microscope. 

1'he  principle  of  the  instrument,  as  described  by  Mr.  Swift,  is 
that  the  image  of  the  pencil  and  paper  is  received  by  a  prism 
(enclosed  in  the  box  which  projects  on  the 
left-hand  side  of  the  figure),  by  which  it  is 
reflected  to  a  piece  of  neutral-tint  glass  placed 
at  an  angle  of  45°  over  the  centre  of  the  upper 
lens  of  the  eye-piece.  The  neutral-tint  glass 
allows  the  image  of  the  object  in  the  Micro- 
scope to  be  distinctly  seen,  while  that  of  the 
pencil  and  paper  is  at  the  same  time  visible  on 
its  first  surface;  no  second  image  occurs  by 
reflection  from  the  back  surface,  omng  to  the  tint  of  the  glass. 

A  second  disk  of  neutral-tint  glass  can  be  interposed  when  the 
light  requires  to  be  subdued  to  show  the  point  of  the  pencil  distinctly. 
It  will  be  seen  that  in  principle  the  instrument  is  an  adaptation  of 
Nachet's  well-known  form. 

(4)  The  fourth  form  is   that  of  Dr.  Eussell,  which  will  be 


Fig.  5. 


24  Transactions  of  the  Society. 

exhibited  by  Dr.  Millar  this  evening,  and  forms  the  subject  of  a 
separate  paper. 

(5)  Although  not  a  "form  of  camera  lucida,"  yet  it  will  not  be  out 
of  place  while  dealing  with  this  subject  to  call  attention  to  a  modifica- 
tion of  a  method  of  drawing  objects  under  the  Microscope  originally 
described  in  'Hardwicke's  Science-Gossip'  for  1867  (p.  236.)  The 
method  there  suggested  was  to  throw  the  image  formed  by  the 
object-glass  on  to  a  sheet  of  paper  fixed  over  a  piece  of  common 
window-glass  at  one  end  of  a  "  camera  obscura,"  the  Microscope 
being  placed  at  the  other  end,  and  the  eye-piece  removed.  Mr.  H. 
E.  Forrest,  of  Birmingham,  now  suggests  that  a  rectangular  prism 
should  be  placed  over  the  eye-piece  of  a  horizontal  Microscope,  thus 
throwing  the  image  of  the  strongly  illuminated  object  on  to  the 
paper  on  the  table,  the  room  being  darkened.  This  method,  while 
obviously  requiring  powerful  illumination  for  high  powers,  is  said 
to  "  enable  even  diatoms  to  be  drawn  with  a  \  objective." 

I  have  purposely  abstained  from  any  criticism  on  the  various 
methods  above  described,  preferring  to  confine  myself  to  a  simple 
record  of  the  fact  of  their  invention. 


(     25     ) 


IV. — Descrijition  of  a  New  Form  of  Camera  Lucida. 
By  J.  Cunningham  Russell,  M.D.,  Lancaster. 

{Read  11th  December,  1878.) 

The  principle  of  this  instrument  is  that,  in  place  of  the  paper  or 
its  reflection  heing  viewed  by  the  eye  directly  as  in  the  cameras 
hitherto  constructed,  there  is  formed,  by  means  of  a  lens  acting  as 
the  object-glass  of  a  telescope,  a  real  image  of  the  paper  at  the 
same  point  as  the  image  of  the  object  formed  by  the  microscopic 
objective,  and  these  two  images  forming  one  combined  image  are 
viewed  through  the  eye-glass  of  the  Microscope.  The  advantages 
of  this  construction  are  that  the  images  being  as  one  it  is  impossible 
that  the  image  of  the  object  should  shift  even  in  the  least  degree 
upon  that  of  the  paper,  and  that  the  images  being  at  exactly  the 
same  distance  from  the  eye,  they  are  both  in  focus  at  once,  and  there 
is  no  straining  of  the  eye  to  accommodate  it  to  both  object  and  paper, 
as  is  apt  to  occur  with  other  instruments.  It  also  avoids  the 
necessity  of  looking  through  a  small  aperture,  the  ordinary  eye- 


Fm.  2. 


Fig.  ]. 


A 

c 

f 

a 

a.  Tube  filtiii};  into  the  Micro- 
scope. 

&,    Rectangular    reflecting 
prism. 

c.  Horizontal  tubes. 

rf,  Vertical  tub?  (inclined  when 
in  use),  containing 

e,  Eye-piece. 

j'.    Plane    reflector    of  tinted 
glass,  and 

fir.  Telescopic  object-gla.ss. 

ti,  Krecting  prism  attached  to 
the  last. 


piece  being  used ;  and  it  admits  of  a  convenient  inclination  being 
given  to  the  eye-piece  while  the  body  of  the  Microscope  is  upright. 
The  construction  of  this  instrument  is  shown  in  the  accom- 
panying figures  and  is  as  follows  : — A  tube  fits  into  the  tube  of 


26  Transactions  of  the  Socitty. 

the  Microscope  :  at  the  top  of  it  there  is  a  right-angled  prism 
(in  a  box)  which  reflects  the  rays  along  a  horizontal  tube  of  con- 
venient length  ;  this  is  crossed  at  the  end  by  a  vertical  tube,  and 
at  the  intersection  there  is  a  jiiece  of  tinted  glass  which  reflects 
the  rays  up  the  vertical  tube.  In  the  upper  limb  of  the  vertical 
tube  is  inserted  the  eye-piece,  and  in  the  lower  limb  the  convex 
glass  which  acts  as  the  telescopic  object-glass,  and  the  rays  from 
which  passing  through  the  tinted  glass  form  an  image  of  the  paper 
in  the  focus  of  the  eye-piece.  As  this  image  is  inverted,  and  it 
is  necessary  for  easy  drawing  that  it  should  be  erect,  an  erecting 
prism  is  attached  below  the  convex  glass.  In  use  the  tube,  which  I 
have  for  simplicity  called  the  vertical  tube,  is  inclined,  by  a  motion 
round  the  axis  of  the  horizontal  tube,  to  an  angle  of  about  00"^  from 
the  vertical,  so  that  the  lower  face  of  the  erecting  prism  becomes 
nearly  horizontal,  the  paper  is  put  on  the  table  below  it  and 
focussed  by  sliding  the  object-glass  in  or  out.  The  light  on  the 
object  must  of  course  be  suitably  modified  so  that  the  paper  and 
pencil  may  be  distinctly  seen. 

I  do  not  put  forward  this  model  as  the  best  possible  form  in 
which  the  principle  may  be  applied  ;  I  have  no  doubt  it  is  sus- 
ceptible of  many  improvements,  but  the  principle  itself  is,  I  believe, 
a  sound  one.  It  is  equally  applicable  with  the  necessary  modifica- 
tions to  drawing  objects  in  the  field  of  a  telescope. 

Lenses  may  be  used  to  erect  the  image  instead  of  a  prism. 


(     27     ) 

V. — Immersion  Illuminators.     By  J.  Mayall,  jun.,  F.E.M.S. 
(^Read  8th  January,  1879.) 

The  need  of  special  apparatus  for  illiiminatiug  objects  mounted  in 
balsam,  or  other  refractive  medium,  seems  to  have  been  clearly  in 
Mr.  Wenham's  mind  when  he  contributed  his  paper  on  "  Illuminating 
Opaque  Objects  "  to  the  '  Transactions'  of  the  Society  in  1856.  The 
appliances  then  described  were,  a  right-angled  prism,  a  truncated 
hemispherical  lens,  used  with  his  paraboloid,  and  the  "  paraboloid 
of  solid  glass  with  a  flat  top."  These  were,  strictly  speaking,  im- 
mersion illuminators:  the  last  is  the  original  "immersion  para- 
boloid." It  was  shown  by  diagrams  that  the  illuminating  rays 
were  made  to  impinge  on  the  upper  internal  surface  of  the  cover-glass 
at  an  inclination  beyond  the  "  critical  angle  "  (or  flat-plate  limit 
between  glass  and  air),  and  reflected  by  total  rejlexion  upon  the 
object,  which  is  then  seen  in  a  dark  field. 

The  reflex  illuminator  designed  by  the  same  inventor,  sixteen 
years  later,  was  based  on  the  same  princij)le. 

With  these  appliances,  used  according  to  the  principle  of  con- 
struction, dark-ground  illumination  is  produced  with  diy  objec- 
tives, whether  the  illuminating  rays  are  internally  reflected  from 
the  cover-glass  on  to  the  balsamed  object,  or  the  object  is  capable 
of  deflecting  the  direct  rays  from  the  illuminator  so  as  to  become 
self-luminous  and  visible  by  means  of  what  may  be  termed  scattered 
rays. 

It  has  been  generally  held  that,  as  stated  by  Mr.  Charles  Brooke, 
"  the  more  minute  structure  of  some  objects  is  cognizable  onhj  by 
its  influence  on  rays  traversing  the  object  at  considerable  obliquity." 
To  this  end  many  appliances  have  been  designed  to  be  used  with 
dry  objectives.  In  Amici's  prism,  Nachet's  prism,  the  truncated 
paraboloids,  right  -  angled  prism,  truncated  hemispherical  lens, 
Reade's  dark-ground  illumination,  the  ''  kettle-drum  "  diatom-prism, 
the  reflex  illuminator,  and  others  too  numerous  to  mention,  we  have 
either  the  use  of  an  actual  stop  to  block  out  portions  of  the  rays,  or 
the  illuminator  is  placed  in  such  a  position  as  to  provide  light  in 
particular  directions.  The  main  purpose  in  all  is  to  utilize  the 
more  obliquely  incident  light  to  the  exclusion  of  the  central. 

On  the  importance  of  regulating  the  obliquity  of  the  illumination 
on  the  object  in  its  relation  to  the  apertures  of  dry  objectives,  I 
quote  from  Mr.  Wenham's  paper  "  On  the  Illumination  of  Ob- 
jects ..."*:— 

"  Practically  it  is  found  that  there  is  a  precise  but  different 
angle  of  illumination  required  for  every  aperture  of  the  object-glass, 
in  order  to  give  the  maximum  of  distinctness ;  or  that  will  even  at 

♦  'Quart.  Journ.,'  1854,  vol.  ii.  p.  152. 


28  Transactions  of  the  Society. 

all  develop  the  markings  on  difficult  tests.  For  if  we  continue  to 
increase  the  angle  of  the  mirror  [he  refers  to  diagram]  the  object 
first  acquires  a  pearly  appearance,  and  is  afterwards  seen  in  a  dark 
field  known  as  '  Keade's  back-ground  [black-ground  ?]  illumina- 
tion' ....  but  the  markings  have  again  become  indistinct  or 
disappear  altogether,  showing  that  it  is  needful  to  allow  a  small 
portion  of  the  light  from  the  source  of  illumination  to  pass  into  the 
object-glass,  and  through  the  object,  that  the  striae  may  either  be 
rendered  more  visible  by  the  rays  that  they  intercept,  or  that  the 
field  shall  be  partly  luminous." 

Withiu  the  last  few  years  the  apertures  of  objectives  have  been 
so  considerably  extended  by  means  of  the  immersion  system,  that, 
in  order  to  utilize  their  fullest  power,  it  has  been  found  neces- 
sary to  use  an  immersion  system  of  illumination.  By  these  means 
we  obtain  direct  rays  (i.  e.  rays  other  than  those  merely  deflected 
by  the  object)  from  the  illuminator  at  greater  inclination  than  the 
critical  angle,  which  certain  of  these  immersions  will  transmit,  pro- 
ducing a  luminous  field. 

When  the  object  is  in  balsam,  and  the  base  of  the  slide  plane 
and  in  air,  no  rays  can  reach  it  from  beneath  at  an  obliquity  greater 
than  the  limiting  angle  for  balsam.  In  order  that  direct  rays  may 
enter  the  balsam  beyond  the  inclination  of  41°,  we  must  have 
recourse  to  an  immersion  condenser,  or  something  equivalent. 

But  it  must  not  be  supposed  that  the  limiting  angle  at  which 
rays  could  be  admitted  into  balsam  from  beneath,  through  a  flat 
plate  of  glass,  imposes  the  same  limit  to  the  angle  up  to  which  an 
immersion  objective  could  collect  image-forming  rays,  supposing 
them  to  have  got  into  the  balsam, — which  assumes  that  the  image- 
rays  above  the  object  are  limited  by  the  angle  of  the  direct  illumi- 
nating rays  from  beneath.  This  erroneous  view  has  had  some 
currency,  and  may  be  thus  stated  : — Because  the  object  in  balsam 
cannot  receive  light  from  beneath  beyond  the  hmiting  angle 
for  balsam,  unless  wo  have  an  immersion  system  of  illumination 
(supposing  the  base  of  the  slide  plane  and  in  air),  therefore  there 
are  no  rays  from  the  object  beyond  that  limit  to  be  transmitted  by 
the  immersion  objective,  however  great  its  aperture ;  the  question 
arising — '"  Where  can  such  rays  come  from  ?  " 

It  is  evideut  that,  independently  of  the  angular  direction  of  the 
illuminating  rays,  if  there  be  an  object  in  the  field  capable  of 
scattering  (and  not  merely  intercepting)  light,  it  is  seen  luminous 
by  scattered  rays.  Kegarded  then  as  a  self-luminous  object,  rays 
are  nascent  therefrom  and  scattered  equally  in  all  directions,  and 
therefore  at  greater  inclination  than  41°.  There  is  no  theoretical 
difficulty  in  their  reaching  the  second  surface  of  the  front  lens  of 
an  immersion  of  suitable  form,  and  in  their  being  transmitted. 
They  cannot,  however,  take  part  in  the  formation  of  the  image  by 


Immersion  Illuminators.     By  J.  Mayall,  jun.  29 

a  dry  objective,  because  they  are  internally  reflected  by  the  cover- 
glass.  These  rays  must  be  regarded  as  important  for  dehcate 
markings,  as  evidenced  by  comparing  the  definition  we  obtain  with 
the  highest-angled  immersions  and  dry  objectives  on  a  balsamed 
object  with  ordinary  illumination, — that  is  to  say,  when  the  base  of 
the  slide  is  plane  and  in  air. 

The  utilization  of  the  whole  of  the  very  large  cone  of  rays  that 
might  be  condensed  on  the  object  by  using  an  immersion  illuminator 
having  an  aperture  equal  to  that  of  the  objective,  in  other  words, 
the  direct  illumination  of  the  whole  aperture,  is  not  the  problem 
that  has  engaged  the  attention  of  those  who  have  endeavoured  to 
exhibit  the  fullest  power  of  the  apertures  of  immersions.  It  was 
long  ago  found  that  it  is  not  so  much  mere  quantity  of  light  that 
is  required  on  the  object,  as  diflerence  of  illumination  that  can  be 
rendered  perceptible  by  the  eye.  The  more  difficult  images  are  seen 
only  as  we  utilize  the  extreme  marginal  aperture  of  the  objective 
and  the  more  oblique  direction  of  the  illuminating  pencil.  This 
can  only  be  done  practically  by  excluding  all  excess  of  central  light. 
The  objects  on  which  the  fullest  power  of  the  aperture  is  needed 
are  generally  so  nearly  of  the  same  refractive  index  as  the  fluid  in 
which  they  are  immersed,  that  there  is  difiiculty  in  making  delicate 
differences  of  transparency  perceptible.  The  immersion  system  of 
illumination  becomes  all-important  to  this  end,  as,  by  it,  any  required 
degree  of  intensity  of  light  can  be  got  upon  the  immersed  object  at 
the  most  favourable  obliquity  for  the  aperture  of  the  objective. 

It  is  found  in  practice  that  to  obtain  the  fullest  effect  on  the 
object,  of  the  extra-ohYio^we  rays  provided  by  immersion  illumination, 
the  objective  must  have  an  aperture  capable  of  transmitting  them,  so 
that  the  field  is  luminous  ;  they  thus  become  a  practical  proof  of  the 
extent  of  the  aperture.  It  follows  also,  as  matter  of  observation,  that 
up  to  the  angle  to  which  the  objective  refracts  the  direct  rays  from 
the  illuminator  to  a  luminous  field,  to  that  angle  (or  very  nearly  so) 
it  refracts  image-rays  from  the  object ;  for  we  find  that  increasing 
the  obliquity  of  the  direct  illuminating  rays  so  as  to  approach  to 
the  dark-field  produces,  at  the  same  time,  distortion  of  the  image, — 
showing  that  both  systems  of  rays  traverse  the  objective  together. 

The  angle  of  the  direct  illuminating  rays  must  not,  however,  be 
regarded  as  an  essential  condition  of  the  existence  of  the  aperture 
(as  such).  It  proves  the  extent  of  the  aperture  of  the  objective  by 
direct  transmission  ;  its  effect  in  rendering  visible  minute  structure 
is  plainly  matter  of  experience, — and  experience  shows  that,  so  far 
as  apertures  have  been  carried,  the  gain  has  been  in  proportion  to 
their  capacity  for  direct  transmission. 

It  will  be  understood  that  I  refer  only  to  objectives  in  which 
the  corrections  have  been  made  to  the  fullest  extent  of  the  aperture  ; 
for  it  must  be  agreed  that  there  is  no  such  thing  as  ajjerture, 


30  Transactions  of  the  Society/. 

properly  speaking,  unless  the  image  of  a  point  be  rendered  as,  ap- 
proximately at  least,  a  point. 

Now,  although,  as  I  have  shown  above,  Mr.  Wenham  understood 
the  need  of  special  means  for  illuminating  obliquely  objects  in 
balsam,  and  the  importance  of  the  angle  of  illumination  in  relation 
to  the  aperture  of  the  dry  objective,  I  do  not  think  he  can  be 
credited  with  having  understood  (much  less  foreseen)  the  important 
part  the  immersion  illumination  of  balsamed  objects  would  take  in 
the  development  of  the  fullest  power  of  immersion  apertures. 
Indeed,  as  he  has  contended  that  the  82°  Uiuit  of  dry  objectives 
obtains  equally  in  immersions,  he  must  be  held  to  deny  the  existence 
of  any  aperture  beyond  S'Z° :  consequently,  the  application  of  the 
immersion  illuminators  above  mentioned,  for  directly  utilizing  any 
such  aperture,  must  be  regarded  as  a  discovery  quite  apart  from  his 
original  application  of  them  for  dark-ground  illumination. 

It  appears  to  me  that  to  Mr.  Tolles  is  due  the  merit  of  first  ap- 
plying immersion  illuminators  to  balsamed  objects  in  connection 
with  immersion  objectives  for  the  distinct  purpose  of  utilizing  by 
direct  transmission  the  excess  of  "  interior  angle  "  beyond  82^.  He 
was  the  first  to  produce  objectives  having  interior  angle  considerably 
beyond  82^,  and  to  demonstrate  their  advantages.  With  these  ob- 
jectives a  luminous  field  was  obtained  when  the  whole  of  the  illu- 
minating rays  that  can  enter  into  a  dry  objective  were  blocked  out, 
and  none  but  rays  beyond  this  limit  admitted :  thus  exhibiting  at 
once  a  luminous  field  and  a  definition  of  immersed  objects  by  means 
of  the  extra  aperture  that  had  not  been  seen  before.  He  appears 
to  have  experimented  chiefly  with  the  semi-cylinder,  because  of  the 
facility  it  offered  for  immediately  obtaining  a  reading  of  the  precise 
degree  of  inclination  the  illuminating  rays  made  with  the  axis,  so 
as  to  determine  the  actual  limit  of  the  apertures  of  the  objectives 
he  had  devised ;  the  display  of  difficult  test-objects  being  merely 
incidental  to  his  efforts  to  improve  the  instrument. 

Dr.  Woodward  has  given  special  prominence  to  the  principle  of 
the  immersion  illumination,  in  its  immediate  connection  with  the 
development  of  the  power  of  aperture,  by  his  "  simple  device,"  in 
which  he  originally  provided  means  to  exclude  all  rays  of  less  incli- 
nation in  glass  than  45*^  from  the  axis,  so  that  no  objective  having 
"interior  angle"  less  than  9 O'' would  give  a  luminous  field  with  it : 
it  thus  aflbtds  a  proof  of  his  position  in  the  aperture  question. 
Viewing  it  as  an  illuminator  only,  Dr.  Woodward  has  simplified  the 
mode  of  mounting  the  prism,  and  slightly  varied  the  angle  in  a 
second  prism  :  his  last  paper  referred  to  these  changes.  I  was 
also  led  to  design  a  modification  of  this  device,  which  is,  briefly,  to 
utilize  the  four  exposed  surfaces  of  the  prism  by  cutting  them  at 
different  angles  so  as  to  approximate  nearly  to  the  semi-aperture  of 
the  objectives  likely  to  be  used.     This  purpose  is  attained  with  a 


Immersion  Illuminators.     By  J.  May  all,  jun.  31 

success  approaching  perfection  in  Tolles's  "  traverse-lens,"  which  I 
hope  to  place  before  you  shortly  with  the  inventor's  notes. 

Many  experimental  devices  have  been  made  for  the  same  pur- 
pose. At  the  last  meeting  I  exhibited  another  modification  I  had 
had  made  of  Dr.  Woodward's  "  simple  device  "  ;  also  a  nearly  hemi- 
spherical lens  and  a  small  semi-cylinder  conveniently  adapted  for 
use  on  the  sub-stage. 

I  mention  Hyde's  oblique  illuminator  for  its  novelty  in  com- 
bining a  condenser  with  prism-illumination.  It  is  a  right-angled 
prism  with  a  lens  of  short  focus  cemented  on  the  long  face,  and  will 
give  a  beam  of  condensed  light  up  to  a  high  degree  of  obliquity. 
Caj)tain  Tupman  brought  it  from  America  four  years  ago.  I  am 
not  aware  whether  the  inventor  designed  this  for  the  purpose  of 
utilizing  by  direct  transmission  the  ea'^ra-oblique  rays  that  can  be 
utilized  only  by  immersions  having  "  interior  angle  "  beyond  82^, 
or  he  intended  such  rays  to  produce  dark-ground  illumination 
only.  The  plan  is  ingenious.  I  have,  however,  found  by  cementing 
a  small  lens  on  one  of  the  exposed  faces  of  Dr.  Woodward's  prism 
the  same  results  are  obtained  more  conveniently. 

I  refer  also  to  a  plan  of  illumination  which  Captain  Tupman 
informs  me  is  due  to  Mr.  ToUes.  It  consists  of  placing  a  suitable 
prism  in  immersion- contact,  on  the  surface  of  the  balsamed  slide,  so 
that  rays  from  a  bull's-eye  lens  may  pass  directly  to  the  internal 
surface  of  the  base  of  the  slide  at  an  inclination  beyond  the  critical 
angle,  they  are  then  totally  reflected  to  the  object.  This  requires 
some  care  in  the  manipulation. 

Professor  Abbe  has  adopted  the  use  of  a  small  lens  *  placed  in 
immersion-contact  with  the  base  of  the  slide ;  which  is  a  very 
simple  and  eflfective  plan,  and  has  been  known  for  some  years  past. 
It  is  really  so  practical  as  almost  to  supersede  the  more  elaborate 
contrivances  for  use  beneath  the  stage. 

Lastly,  I  refer  to  a  reflecting  immersion  illuminator  which  I 
have  suggested  to  Professor  Abbe,  and  which  he  has  undertaken  to 
have  made  for  me  by  Mr.  Zeiss :  this  w  ill  be  placed  before  you 
when  completed. 

Immersion  illuminators  are  designed  to  secure  a  particular  an- 
gular direction  to  the  illuminating  rays  while  actually  in  the  body  of 
the  fluid  in  which  the  object  is  immersed,  with  a  view  to  utilizing 
incident  light  of  great  obliquity  ;  used  in  connection  with  the  highest- 
aijgled  immersion  objectives,  they  have  given  fair  grounds  to  expect 
that  the  future  of  the  most  difficult  investigations  in  microscopy  will 
be  largely  dependent  on  their  successful  aj^plication. 

*  At  the  Meeting  in  June  I  erroneously  stated  that  Mr.  Wenham  hail  used  a 
siniilar  lens  for  the  same  purpose  many  years  ago.  He  used  the  leus  for  reflex 
illumination  from  the  cover-o;lass — «  >/  for  d  rcct  illumination. 


82  Transactions  of  the  Societij. 


VI. — Note  on  a  Bevoher  Imme7'sion  Prism  for  Svh-stage 

Illumination. 

By  James  Edmunds,  M.D.,  M.E.C.R  Lond.,  F.E.M.S.,  &c. 

(^Read  8th  January,  1879.) 

The  value  of  a  right-angled  immersion  prism  as  a  sub-stage  appli- 
ance for  the  illumination  of  objects  under  the  Microscope  was  shown 
by  Mr.  Wenham  in  the  year  1855',  in  a  paper*  published  in  the 
'  Transactions  of  the  Eoyal  ]\Iicroscopical  Society.'  Mr,  Wenham's 
paper  is  illustrated  with  a  woodcut  showing  a  right-angled  prism 
attached  to  the  under  surface  of  a  slide  by  means  of  oil  of  cloves, 
balsam,  turpentine,  or  camphine ;  light  concentrated  by  a  bull's- 
eye  being  deflected  upwards  by  means  of  an  Amici  prism.  In  the 
same  paper  Mr.  Wenham  also  shows  how,  by  means  of  a  hemi- 
spherical lens,  or  "  a  small  paraboloid  of  glass  with  a  flat  top  " 
similarly  attached  to  the  under  surface  of  the  slide,  other  methods 
of  immersion  illumination  may  be  made  effective  and,  as  he  says, 
"  show  the  DiatomacefB  with  a  degree  of  beauty  and  delicacy  that  he 
had  never  seen  equalled." 

The  Tolles  Microscopes  have  now  for  some  years  had  fitted  to 
their  stages  deep  spherical  and  cylindrical  lenses  to  be  used  for 
immersion  illumination,  and  the  splendid  oil  lenses  now  made  by 
Zeiss  are  sent  out  accompanied  by  a  small  lens  to  be  attached  to 
the  under  surface  of  the  slide  with  cedar  oil,  in  order  to  supj)ly 
light  on  the  same  principle.  Colonel  "Woodward  also  has  re- 
cently favoured  this  Society  with  two  paners  developing  this  most 
valuable  method  of  illumination  for  high-angled  lenses,  and  he  has 
combined  with  the  right-angled  immersion  prism  two  screens  of 
thin  metal  perforated  in  line  with  ihe.  object,  so  that  entering  light 
may,  when  necessary,  be  demonstrably  limited  to  parallel  rays  at 
a  determinate  angle. 

The  oil  of  cloves,  UFed  as  an  intermedium  by  Mr.  Wenham,  has 
been  adopted  by  Colonel  Woodward.  Cedar  oil,  castor  oil,  or  pure 
glycerine  (Price's)  also  answer  perfectly.  As  to  the  hght,  it  will 
be  found  that  a  1^-inch  achromatic  objective  serves  much  better 
as  a  condenser  than  a  bull's-eye,  and  that  an  image  of  the  edge  of 
a  parafiin-lamp  flame  should  be  accurately  condensed  upon  the 
object. 

I  now  have  the  honour  to  submit  a  new  combination  prism,  con- 

*  "  On  a  Method  of  Illuminating  Objects  under  the  Highest  Powers  of  the 
Microscope."  By  F.  H.  Wenham,  Esq.  Read  March  25,  1856.  '  Transactions  of 
the  Royal  Microscopical  Society,'  vol.  iv.  pp.  55-GO. 


Revolver  Immersion  Prism.     By  James  Edmunds.  33 

structed  for  me  by  Messrs,  Powell  and  Lealand,*  which  will,  I  think, 
be  found  to  render  immersion  illumination  more  manageable  and 
more  generally  useful.  I  have  termed  it  the  revolver  prism, 
because,  by  its  means,  unrefracted  light  at  four  grades  of  obliquity 
may  be  successively  thrown  into  the  object  simply  by  rotating  the 
prism  and  altering  the  inclination  of  the  Microscope.  This  prism 
is  of  hard  white  crown  glass,  and  six  or  seven  eighths  of  an  inch  in 
diameter.  Above,  it  has  a  circular  plane  surface,  with  a  border 
curving  downwards  so  as  to  afford  hold  for  a  setting  which  does  not 
rise  high  enough  to  touch  the  slide.  Below,  it  has  four  facets 
produced  by  grinding  down  a  spherical  surface  into  two  right- 
angled  prisms,  whose  lower  edges  are  located  at  right  angles  to 
each  other,  and  whose  faces  respectively  make  with  the  top  surface 
angles  of  30°  and  60°,  41°  and  49°.  These  four  facets,  taken  con- 
secutively, are  normal  to  light  entering  at  30°,  41°,  60°  and  49° 
of  obliquity  to  the  optic  axis.  The  prism  is  sprung  into  the  top  of 
a  vertical  tube  deeply  slotted  for  the  passage  of  light  to  the  various 
facets,  each  slot  being  cut  down  to  a  line  at  which  the  side  of  the 
tube  would  be  intersected  by  the  plane  of  the  facet  on  the  opposite 
side.  Below,  the  tube  screws  or  slides  into  an  adapter,  or  expands 
into  a  ring  for  the  sub-stage.  The  top  surface  of  the  prism  connects 
to  the  slide  by  means  of  a  minim  of  cedar  oil  or  Price's  glycerine, 
and  glare  is  prevented  by  the  fact  that  superfluous  light  is  reflected 
out  through  the  slot  behind.  Each  slot  is  figured  with  the  obli- 
quity of  the  light  for  which  it  is  cut,  and  by  a  simple  addition  the 
entering  light  may  be  demonstrably  limited  to  a  particular  angle, 
as  with  Dr.  Woodward's  perforated  screens. 

By  means  of  this  immersion  prism  the  obliquity  of  the  illumi- 
nation may  be  so  graduated  as  to  shut  out  the  light  field  and  the 
ordinary  negative  image  in  so  far  as  is  necessary  to  obtain  the  diffrac- 
tion image  at  its  best  jDoint.  With  light  at  60°  from  the  optic  axis 
the  diffraction  image  is  so  far  isolated  that  Ampliipleura  pellucida 
in  balsam  may  be  seen  upon  a  dark  background  with  the  new  oil 
lens.  With  hght  at  49°  or  41°  the  field  becomes  lighted  in  propor- 
tion to  the  angular  aperture  of  the  objective,  and  the  diatom  is 
finely  displayed,  but  with  light  at  30°  the  lines  disappear. 

Amjjliiiyleura  peUuclda  in  air,  whether  upon  cover  or  slide,  may 
also  be  shown  by  this  jtrisin.  If  the  diatom  be  upon  the  slide,  an 
intense  black-ground  illumination  may  be  produced  through  the 
higher-angled  facets,  and  the  lines  are  shown  as  green  and  black 
bands,  as  they  are  by  means  of  the  immersion  paraboloid.f  If  the 
diatom  be  upon  the  cover,  the  two  lower-angled  facets  will  show  it, 

*  I  exliibited  this  prism  on  June  5,  1878,  at  the  soiree  of  the  Metropolitan 
Branch  of  the  British  Medical  Association. 

t  "  On  the  Paraboloid  Illuminator.'     Vide  '  Monthly  Microscui>ic;il  Journal,' 
August,  1877,  p.  SI. 

VOL,    II.  I> 


34  Transactions  of  the  Society. 

but  for  full  illumination  the  facet  at  30°  is  required.  Light 
emerging  from  the  slide  at  30^  is,  of  course,  bent  down  so  as  to 
strike  the  under  surface  of  the  cover  at  about  49°,  and  in  this  light 
the  dry  diatom  may  be  splendidly  resolved.  In  balsam,  light  at 
about  the  same  angle  (49°)  seems  to  resolve  the  diatom  best. 
With  Am2)hi2jleura  pellucida  the  light  should  in  all  cases  strike 
the  diatom  end  on,  or  it  will  not  be  resolvable.  The  brilliancy  of 
the  field  also  must  be  kept  in  due  subordination  to  the  influence  of 
the  difiraction  image,  and  as  the  following  method  of  procedure 
makes  this  very  difiicult  object  quite  easy,  I  may  perhaps  be  per- 
mitted to  describe  it. 

1.  By  means  of  a  four-tenths  objective,  a  diatom  should  be 
selected,  centred,  and  turned  so  as  to  lie  exactly  north  and  south 
in  the  field. 

2.  If  light  at  49°  is  needed,  the  corresponding  facet  of  the 
prism  should  be  turned  to  the  front.  The  Microscope  tube  should 
be  inclined  through  the  complementaiy  angle  (41^),  so  that  the 
facet  stands  vertical. 

3.  The  lamp  flame— edge  on — should  be  set  on  a  level  with  the 
object,  and  at  eight  inches  distance. 

4.  A  n-inch  achromatic  objective  should  be  arranged  in  line, 
so  as  to  condense  upon  the  object  a  fine  image  of  the  lamp  flame. 
In  order  to  show  that  the  image  of  the  flame  is  accurately  focussed 
upon  the  object,  a  piece  of  wet  tissue-paper  may  be  laid  upon  the 
top  of  the  slide,  or  the  image  of  the  flame  upon  the  face  of  the 
observing  lens  may  be  viewed  through  a  side  facet. 

Under  these  circumstances  the  lines  will  be  perfectly  resolved 
if  the  lens  have  an  adequate  angular  aperture  and  he  properly 
adjusted.  The  method  is  very  simple,  but  for  want  of  it  I  have 
seen  an  experienced  manipulator  spend  hours  in  ''  fiddling  about  for 
the  lines,"  and  utterly  exhaust  his  eyes  without  determining 
whether  or  not  the  optical  capacity  of  the  lens  on  trial  was  at  fault. 
By  the  method  I  have  described,  this  difiicult  object  may  be  re- 
solved as  easily  as  a  Podura  scale.  If,  when  the  lines  are  properly 
resolved,  the  eye-piece  be  taken  out,  there  will  be  seen,  on  looking 
down  the  tube,  at  the  southern  edge  of  the  field,  a  small  clear 
image  of  the  flame,  and  at  the  northern  edge — diametrically  oppo- 
site— a  soft,  greenish-blue  diffraction  image.  Sometimes  also  an 
outline  of  the  diatom  crossing  the  field  from  one  image  to  the  other 
may  be  discerned. 

The  particular  angles  given  to  the  prism  now  before  the  Society, 
were  selected  in  order  to  enable  a  single  prism  to  command  the 
whole  range  of  oblique  illumination,  and  to  enable  so  difficult  an 
object  as  Amjjhipleura  ]jeUticida  to  be  at  once  resolved  whether  in 
balsam  or  in  air,  and  whether  upon  the  slide  or  upon  the  cover. 
Through  these  facets,  light  at  somewhat  different  angles  may  be 


Revolver  Immersion  Prism.     By  James  Edmunds.         35 

pas^sed  without  practical  detriment,  as  only  the  edges  of  the  beam 
would  become  chromatized,  or  other  angles  may  be  given  to  the 
revolver  prism.  If  two  such  prisms  were  to  accompany  the  Micro- 
scope, one  might  be  cut  at  angles  of  25°,  30°,  35^,  and  40°,  in  order 
to  light  objects  to  be  viewed  under  high-angled  light  in  air  on  the 
cover,  or  under  low-angled  light  if  in  balsam.  The  second  prism 
might  be  cut  at  40^,  45",  50°,  and  55°,  in  order  to  liglit  objects  to 
be  viewed  on  the  slide  in  air  with  black  background,  or  under  the 
highest  working  angular  apertures  if  in  balsam.  Difficult  objects, 
when  set  uj^on  the  slide  in  air  for  black-ground  illuminatioi],  re- 
quire the  cover  to  be  very  close  down  upon  them,  or  they  will  not 
be  resolvable  by  high-angled  lenses. 


36  Transactions  of  the  Society. 


VII. — A  Catoptric  Immersion  Illuminator. 
By  John  Ware  Stephenson,  F.KA.S.,  Treas.  E.M.S. 

[Read  8th  January,  1879.) 

As  the  subject  of  Immersion  Illuminators  is  now  before  the  Society 
(and  I  am  very  glad  it  is  so,  for  without  their  help  the  full  resolving 
powers  of  the  recent  large-angled  objectives  cannot  be  utilized),  it 
may  not  be  out  of  place  to  lay  before  the  Fellows  a  brief  account  of 
an  immersion  condenser  of  very  simple  construction  which  I  devised 
in  1877. 

The  diagram  shows  the  form  and  size  of  the  instrument  which 
I   now  use,  although  it  is  sufficiently  obvious  that  other   sizes, 
in  the  same  ratios,  may  easily  be  made — in 
fact,  I  have  such. 

The  apparatus  is  simply  a  plano-convex 
lens,  worked  on  a  1-inch  tool,  and  having  a 
diameter  of  1  •  2  inches,  which  is  then  "  edged  " 
down  to  1  inch,  as  being  more  convenient  in 
size,  and  as  giving  an  aperture  sufficient  for 
our  purpose. 

The  upper,  or  convex  side,  of  the  lens  is 
cut  down  or  flattened,  so  as  to  give  a  surface  y\  of  an  inch  in 
diameter,  with  Avhich  the  slide  is  to  be  connected,  when  in  use,  by 
a  drop  of  oil  or  water. 

It  matters  not  which  fluid  is  used  as  long  as  the  objective  has  a 
numerical  aperture  not  exceecling  1'33  (the  index  of  water),  and 
it  is  very  improbable  that  this  will  ever  be  exceeded  to  any  great 
extent,  as  1  ■  50  is  the  ideal  maximum  of  even  an  oil  immersion. 

The  upper  curved  surface  of  the  lens  is  silvered,  and  beneath 
the  lens,  a  flat  silvered  plate  -^^  of  an  inch  thick,  and  correspond- 
ing in  size  and  position  with  the  upper  flattened  surface,  is  balsamed. 
It  will  be  seen  that  the  incident  ray  is  normal  to  the  under 
surface,  impinges  on  the  curved  silvered  surface,  and  is  thus  thrown 
back  on  the  plane,  or  under  surface  of  the  lens,  whence  the  more 
oblique  rays,  falling  beyond  the  critical  angle,  are  totally  reflected, 
and  converge  to  a  focus,  giving  a  numerical  angle  of  1  '30  =  120° 
in  balsam. 

The  object  of  placing  a  silvered  glass  disk  beneath  the  lens  is 
twofold :  in  the  first  place,  it  reflects  the  less  oblique  rays  which 
fall  within  the  critical  angle,  and  in  the  second  it  tends  to  diminish 
the  spherical  al;erration  which  in  this  zone  might  otherwise  be  felt. 
The  stop  is  placed  about  \  of  an  inch,  or  less,  below  the  con- 
denser, and  the  opening  used  is  of  a  lens-shaped  form,  as  giving 
a  broad  beam  without  any  appreciable  spherical  aberration  in  so 
narrow  a  zone  of  light. 


A  Catoptric  Immersion  lUuminator.     Bij  J.  W.  Stephenson.     37 

It  will  be  found  that  this  instrument  will  work  through  any 
ordinary  glass  slip,  gives  a  brilliant  light,  and,  having  no  refracting 
surface,  is  necessarily  achromatic,  whilst  the  spherical  aberration,  as 
previously  pointed  out,  is  inconsiderable. 

If  used  with  a  dry  lens  of  the  highest  power  on  a  balsam- 
mounted  object,  the  light,  unable  to  pass  the  upper  surface  of  the 
covering  glass,  is  thrown  back  on  the  object,  giving  opaque  illumi- 
nation ;  on  the  other  hand,  with  dry  objects  adhering  to  the  slide, 
the  well-known  dark-ground  illumination  can  be  obtained  with  any 
objective  I  have  yet  seen. 


38  Transactions  of  the  Socieiy. 

VIII. — The  Thallus  of  the  Diatomacem. 
By  F.  KiTTON,  Hon.  F.E  M.S. 

{Iiead  8th  January,  1879.) 

The  study  of  the  living  diatom  has  lately  engaged  the  attention  of 
many  eminent  foreign  diatomists  (M,  P.  Petit,  Paris ;  M.  J,  Deby, 
Belgium  ;  Count  Castracane,  M,  Ardres,  and  others).  The  latest 
published  observations  are  those  of  M.  le  Dr.  Lanzi,  of  Eome,  in 
his  paper*  on  the  "  Thallus  of  the  Diatomaceae."  By  thallus  is  to 
be  understood  the  stipes,  cushion,  tube,  frond,  or  mucous  pellicle. 
The  latter  is  the  material  by  which  the  film  of  diatoms  is  attached 
to  wet  walls,  buttresses  of  bridges,  &c.  He  communicates  some 
interesting  facts  connected  with  the  reproduction  of  these  remarkable 
organisms.  "  In  a  gathering  of  Epithemia  ventricosa  made  in  the 
Villa  Pamphilia,  in  Eome,  I  observed  that  some  portions  of  the 
pellicle  were  composed  of  a  great  quantity  of  round  granular  cor- 
puscles of  a  greenish-yellow  colour.  Most  of  these  corpuscles  were, 
to  all  appearance,  the  same  as  those  contained  in  the  interior  of  the 
frustules  of  the  Epithemia,  and  imbedded  in  a  hyaline  plasma. 
Such  was  the  resemblance,  that  no  one  could  doubt  that  the 
granular  bodies  in  the  plasmatic  thallus  and  those  in  the  frustules 
were  alike. 

"At  another  time  I  made  a  gathering  in  a  fountain  in  the 
interior  of  the  Forum  of  Trajan,  of  a  Cymbella  in  a  state  of 
reproduction,  and  I  was  again  able  to  see  the  round  corpuscles. 
They  were  very  small,  and  of  the  same  colour  as  the  endochrome. 
They  were  contained  in  the  thallus,  and  resembled  those  in  the 
frustules.  I  followed  these  germs  through  their  phases  of  develop- 
ment ;  and  by  repeated  observations  I  ascertained  that,  whilst  in- 
creasing in  breadth,  they  preserved  their  circular  form  ;  that  after- 
wards they  commenced  to  elongate,  in  order  to  acquire  the  lunate 
and  naviculoid  outline  of  the  mature  frustule. 

"  Of  these  growing  forms,  some  remained  attached  to  the  thallus, 
and  some  became  free.  The  number  of  these  corpuscles  was  con- 
siderable ;  and  one  was  easily  convinced  that  they  were  the  result 
of  a  new  kind  of  generation.  The  disparity  in  size  was  so  consider- 
able, that  it  would  have  been  absurd  to  suppose  that  they  had  been 
produced  by  fissiparity. 

"  I  am  able  to  report  other  similar  facts  observed  in  Navicula 
amhigua,  Nitzschia  minutissima,  Amphora  ovalis ;  but  of  these  I 
shall  say  nothing,  in  order  to  avoid  useless  repetitions,  and  shall 
confine  myself  to  describing  Gomphonema  oUvaceum  only,  in  which 
I  have  followed  the  series  of  transformations  from  the  time  the 
frustule  containing  the  germs  had  changed  into  a  sporangial  cell, 

*  See  '  Annales  de  la  Socie'te'  Beige  de  Microscopie,"  vol.  iv. 


The  Thallus  of  the  Diatomacese.     By  F.  Kition.  39 

until  the  thallus  became  charged  with  germs  and  frustules  in  various 
stages  of  development.  In  this  same  thallus  was  also  seen  the 
gradual  transformation  of  the  corpuscles  into  rudimentary  frustules, 
their  growth,  and  lastly  the  development  of  the  dichotomous 
peduncle.  When  this  cycle  was  completed,  the  thallus  contained 
three  different  forms — the  sessile  sphenelloid  form,  the  pedunculate 
(either  simple  or  dichotomous),  and  the  perfect  or  free  form.  From 
the  preceding,  it  appears  that  there  arrives  a  time  when  the  plasma 
contained  in  the  siliceous  cells  acquire  a  considerable  volume,  owing 
to  the  rapid  development  manifested  at  the  time  of  reproduction, 
and  which  cannot  be  contained  within  the  walls  of  the  frustule  by 
reason  of  the  want  of  elasticity  produced  by  the  deposition  of  silex. 
The  frustules  being  unable  to  follow  the  growth  of  the  plasma,  the 
valves  separate  from  the  pressure ;  but  previous  to  arriving  at  this 
condition,  the  protoplasm  had  commenced  to  undergo  the  changes 
necessary  to  the  formation  of  the  new  cellules,  and  we  are  able  to 
see  an  aggregation  of  hyaline  masses  destitute  of  an  external 
membrane.  These  are  the  Moneres  of  Haeckel.  Amongst  them 
are  some  that  remain  for  a  long  time  as  plastid  gymnocytodes — that 
is  to  say,  without  an  external  membrane,  as  named  by  Haeckel — 
and  form  in  this  manner  the  amorphous  or  indefinite  thallus 
{mucus  matriculis  of  authors) ;  whilst  those  that  take  the  form  of 
stipes,  peduncles,  cushions,  or  some  definite  form,  appear  to  belong 
to  the  plastid  lepocytodes,  that  is  to  say,  invested  with  an  extremely 
thin  external  membrane.  This  membrane,  although  scarcely  visible 
with  the  Microscope,  nevertheless  Umits  the  outline  of  the  thallus. 
...  I  have  determined  to  place  the  above-mentioned  facts  before 
diatomists,  in  order  to  call  their  attention  to  the  study  of  the  thallus 
of  diatoms.  The  study  of  the  function  of  the  thallus  in  this  large 
family  seems  to  me  to  be  full  of  interest." 

The  presence  of  this  •'  thallus "  is  by  no  means  uncommon. 
I  have  detected  it  in  many  diatomaceous  gatherings,  particularly 
those  from  fresh  water,  but  I  never  saw  the  corpuscles  Dr.  Lanzi 
mentions ;  they  may  not  have  been  present,  or,  what  is  equally 
probable,  I  overlooked  them.  However,  the  discovery  is  of  great 
interest ;  and  I  hope,  with  Dr.  Lanzi,  that  other  diatomists  will 
turn  their  attention  to  the  study  of  the  living  forms.  The  repro- 
duction of  the  Diatomficea3  has  not  received  that  amount  of  atten- 
tion the  subject  deserved.  Their  increase  by  self-division  was  the 
method  first  observed,  more  careful  observations  led  to  the  detection 
of  conjugation  and  production  of  sporangial  frustules,  or  the  for- 
mation of  a  sporangium  by  a  single  frustule  ;  and  we  now  find  that 
another  method  has  been  observed,  viz.  that  just  described  by  Dr. 
Lanzi. 

The  author's  figure  (1)  represents  a  number  of  circular  bodies 
immersed  in  the  thallus  of  E.  rentricosa,  and  also  in  the  frustule ; 


40  Transactions  of  the  Sociefij. 

(2)  thallus  of  Coceonema  cistula,  representiug  the  corpuscles  in 
various  stages  of  development.  Unfortunately  the  amplification  is 
not  stated,  a  matter  of  some  importance.  It  is  also  to  be  hoped 
that  Dr.  Lanzi  will  make  some  experiments  to  test  the  power  pos- 
sessed by  them  to  resist  desiccation  without  losing  their  vitality. 
In  Herr  Grrunow's  "  New  Diatoms  from  Honduras,"  '  M.  M.  J.,' 
vol.  xviii.  p.  184,  PI.  196,  Fig.  4&,  is  described  and  figured  a 
curious  abnormity  of  Gerataulus  lievis.  Within  the  large  frustule 
are  two  very  small  ones.  Herr  Grunow  asks,  "  In  what  manner 
do  these  abnormal  frustules  multiply  and  reproduce  a  new  series 
of  normal  forms?  Certainly  not  by  conjugation  or  self- division." 
Professor  Cleve  *  figures  a  frustule  of  Biddulphia  aurita  with  a 
small  frustule  within.  In  a  note  (p.  184),  I  suggested  "  that  the 
endochrome,  under  certain  conditions,  might  possess  the  power  of 
producing  (?  by  means  of  microspores)  perfect  frustules  without 
conjugation."  Dr.  Lanzi's  discovery  confirms  my  supposition,  and 
explains  the  formation  of  the  small  frustules  within  the  large  one. 

*  '  Bihang  till  Vet.  Akad.  Hand.,'  band  i.  tab.  iv.  fig.  3  a  6. 


(  ^1  ) 

NOTES  AND  MEMOEANDA. 


Researches  on  the  Proboscis  of  Butterflies. — W.  Breitenbach 
has  undertaken  a  series  of  observations  *  on  the  hairs  with  which  the 
proboscis  of  butterflies  is  covered,  and  on  the  relation  of  these  to  the 
curious  "  Cylindergebikle  "  or  sheathed  hairs  by  means  of  which  many 
Lepidoptera  are  enabled  to  pierce  the  tissues  of  plants  for  the  purpose 
of  getting  at  the  contained  juices. 

The  ordinary  typical  hairs  consist  of  a  basal  portion  or  cylinder 
composed  of  a  dark  chitinous  material,  and  either  partly  imbedded 
in  the  substance  of  the  proboscis  or  projecting  freely  from  its  siu*- 
face,  and  of  the  hair  projier,  the  proximal  portion  of  which  is  im- 
bedded in  the  cylinder,  while  the  distal,  usually  by  far  the  larger 
part,  is  free.  In  Zygcena  JiUpendulce  the  hairs  on  the  greater  part  of 
the  proboscis  have  the  ordinary  characters,  but,  near  the  free  end 
of  the  organ,  the  edge  of  the  cylinder  is  jiroduced  into  four  eleva- 
tions, placed  at  equal  distances  from  one  another ;  the  cylinder  itself, 
moreover,  is  proportionally  longer  and  the  hair  proper  proportionally 
smaller  than  in  the  typical  hair.  In  Pieris  a  similar  structure  ob- 
tains, but  the  cylinder  is  strengthened  by  longitudinal  bands,  one 
for  each  of  the  five  points  into  which  its  edge  is  produced,  and  of  a 
darker  colour  and  firmer  consistency  than  the  rest  of  the  cylinder. 
In  Epinephele  Janira,  the  size  of  the  whole  apparatus  is  greatly 
increased,  the  processes  on  the  edge  of  the  cylinder  have  become 
actual  teeth,  and  the  hair  proper  is  so  much  reduced  as  to  form  a  mere 
papilla  just  overtopping  the  circlet  of  teeth.  A  structure  is  thus 
produced  eminently  fitted  for  piercing  the  tissues  of  plants.  A  further 
modification  occurs  in  Arge  Galathea,  in  which,  besides  the  row  of 
teeth  round  the  edge  of  the  cylinder,  there  are  three  other  circlets, 
encompassing,  at  equal  intervals,  its  lateral  surface  :  each  of  the  four 
circlets  is  six-toothed.  In  Catocala  hymencea  the  structure  seems  at 
first  sight  to  be  altogether  different :  the  cylinder  is  provided  with  six 
vertical  plates  standing  out  from  its  lateral  surface,  and  projecting  over 
its  edge  in  the  form  of  sharp  points :  these  plates  may  be  considered 
as  having  been  formed  by  the  coalescence  of  superposed  rows  of  teeth, 
such  as  exist  in  Arge. 

From  these  observations  it  seems  highly  probable  that  the  sheathed 
hairs  have  been  developed  from  ordinary  hairs  by  the  gradual  dimi- 
nution of  the  hair  proper,  especially  of  its  extra-cylindrical  portion, 
and  by  the  simultaneous  increase  in  size  and  strength  of  the  sur- 
rounding cylinder.  The  advantage  accruing  to  the  insect  from  the 
change  is  obvious ;  with  a  proboscis  provided  merely  with  ordinary 
hairs  it  would  be  able  to  take  advantage  only  of  free  nectar,  that  is 
juice  actually  poured  out  by  the  secreting  glands  of  the  plant,  whereas 
with  the  sheathed  hairs  it  would  be  able  to  pierce  the  cell-walls  and 
derive  an  additional  quantity  of  nutriment  by  drawing  upon  the  in- 
ternal juices.  This  view  is  supported  by  the  fact  that  Lepidoptera 
visit  flowers  which  produce  no  free  nectar. 

*  '  Aichiv  f.  Mik.  Anat.,'  vol.  xv.  p.  8. 


Species 


I.  In  the  process  of  division  the 
nucleus  divides   repeatedly, 
and  a  number  of  the  nuclei  { 
thus  formed  pnss  into  each  of 
the  resulting  spheroids. 


B 


42  NOTES    AND    MEMORANDA. 

Contributions  to  our  knowledge  of  the  Protozoa.  —  Professor  A. 
Sclineider  has  a  short  but  important  pajjer  (with  a  plate)  on  this 
subject,  in  the  '  Zeitschrift  f.  wiss.  Zool.,'  *  in  which  he  describes  his 
recent  observations  on  Actinosjjhcerium,  Miliola,  Trichosphcerium  (a 
new  genus),  and  Chlamydomonas. 

Acthiosplicerium  Eichornii.  —  Schneider's  comparison  of  his  own 
researches  with  those  of  Brandt,  Greeff,  and  F.  E.  Schulze,  lead  him  to 
think  that  this  species  really  includes  four  distinct  species,  agreeing 
with  one  anotVier  in  the  vegetative  condition,  and  differing  only  in  the 
reproductive  stage.  The  observations  on  which  this  opinion  is  based 
are  shown  in  the  following  table  compiled  from  Schneider's  paper. 

f  1.  After  the  completion  of  the  process  "j 
of  division,  each  of  the  two  sphe- 
roids Climes  1o  lie  in  a  special 
cyst,  or  rather  in  a  special  com-  1  "^'T 
partmont  of  the  common  cyst :  t 
the    spheroids    do    not    subse- 
quently unite,  and  their  siliceous 
case  is  single  (Schneider). 
After  division  the  two  spheroids' 
do   not,  or  not   always,   lie   in 
special  cavities  in  the  cyst :  after 
the  process  of  division  the  two 
spheroids  unite  again  :  their  sili- 
ceous case  is  double  (GreeiT). 

II.  In    the    process    of    division  /  ^  ^^f^^^.  ^^^^^^^^  ^i^e  spheroids  con-  \     ^ 

the  nucleus  disappears,  new  -^^^  (Brandt).                            /     ^ 

nuclei  afterwards  appearing,  J  ^_  j^.^^,.,^^    ^^     ^j^^    spheroids) 

one  of  which  passes  into  each  \  ^^^^^  ^^^  ^^^^^     ,^^  (Schneider,        D 

spheroid :  the  siliceous  cases  ^  ^  Schulze). 
are  thinner  than  in  (i.).          \ 

A  further  evidence  of  the  distinctness  of  this  form  is  afforded  by 
the  difference  in  their  habits :  of  the  two  observed  by  Schneider,  the 
species  A,  from  the  canal  in  the  Berlin  Zoological  Gardens,  fed  chiefly 
on  Cijdops,  to  which  it  clung  by  its  pseudopodia,  allowing  itself  to  be 
carried  about  by  its  prey  until  the  latter  was  killed :  the  species  D, 
from  ditches  at  Giessen,  never  devoured  Gyclopidaj,  but  fed  chiefly  on 
Chlamydomonas,  and  amongst  higher  animals  confined  itself  to  the 
smaller  Kotatoria, 

2,  Development  of  Miliola. — In  a  species  of  this  genus  observed  at 
Fohr,  distinct  nuclei  were  observed.  Multiplication  took  place  by  the 
protoplasm  being  divided  into  nucleated  masses,  of  which  there  were 
finally  seen  to  be  two  kinds  ;  small  naked  cells,  probably  representing 
spermatozoa,  and  large  oval  cells  provided  with  a  distinct  membrane, 
and  seeming  to  represent  ova.  No  stage  was  found  between  these 
latter,  and ''germ  masses,  consisting  of  a  very  distinct  cell-wall 
enclosing  contents  half  protoplasmic,  half  fat  like.  The  fatty  body 
disappeared,  and  the  germ  was  converted  into  a  young  Miliola,  with  a 
single,  globular,  thin-walled  chamber,  provided  with  one  large  aperture 
ancf  several  small  ones,  through  which  pseudopodia  were- protruded  : 
no  nucleus  was  visible  in  this  stage.  The  tubular  portion  of  the  shell 
was  seen  to  begin  as  a  hand-shaped  process  near  the  mouth.  The 
young  Miliolce  continued  to  grow  through  the  winter,  and  then  the 
*  '  Zeit.sch.  f.  wiss.  Zool.;  vol.  xxx.  (Suppl.),  p.  446. 


NOTES    AND    MEMORANDA.  43 

formation  of  germs  began  anew,  but  this  time,  apparently,  asoxually, 
as  no  sperm-cells  were  seen. 

In  a  vessel  of  sea-water  containing  Miliolce  from  Heligoland,  were 
found  small  sandy  accumulations,  containing  a  transparent,  hardish 
substance,  devoid  of  silica,  and  enclosing  about  fifteen  spaces  containin^^ 
capsules.  The  contents  of  these  capsules  were  of  four  kinds,  firstly,  a 
great  number  of  bright  Eiiglena-like  bodies,  devoid  of  flagella,  but 
exhibiting  movements,  probably  spermatozoa ;  secondly,  masses  of 
protoplasm,  probably  ova  ;  thirdly,  undoubted  young  Miliolfe  ;  and 
fourthly,  some  of  the  capsules  were  empty  and  probably  represented 
empty  sperm-capsules. 

It  will  be  seen  at  once  that  the  evidence  for  the  sexuality  of 
Miliola,  brought  forward  by  Schneider,  is  by  no  means  complete. 

3.  Trichos]}Jicerium  Sieholdii  (nov.  gen.  et  sp.).  —  This  species 
was  discovered  in  water  from  Ostend,  where  it  existed  in  such 
quantities  as  to  form  a  white  powder.  Its  shape  is  generally  ovoidal, 
but  undergoes  considerable  changes,  so  slowly,  however,  that  the 
changes  could  not  be  followed  by  the  eye.  The  surface  is  thickly 
covered  with  long  bristle-like  filaments  (Borsten),  which  are  unaffected 
by  potash,  but  dissolve  in  dilute  acetic  or  hydrochloric  acid,  without 
evolution  of  gas.  When  these  bristles  are  dissolved,  the  animal  is 
seen  to  be  covered  with  a  fine  membrane  produced  into  short  cylindri- 
cal tubular  processes,  through  each  of  which  a  delicate  protoplasmic 
filament,  slightly  longer  than  the  bristles,  is  protruded.  Tricho- 
sphcerium  forms  an  intermediate  genus  between  Lieberkuhnia  and  the 
ordinary  calcareous  Foraminifera. 

4.  Chlamydomonas. — The  author  describes  three  species  of  this  alga, 
C.  pulvisailiis,  C.  tumicla,  and  C.  radiosa,  and  also  gives  an  account  of 
the  conjugation  in  the  first-named  sj)ecies. 

Cochineal  for  Staining.— Dr.  Paul  Mayer,*  of  the  Zoological 
Station  at  Naples,  when  making  experiments  to  find  an  alcoholic 
carmine  solution  with  which  to  stain  satisfactorily  entire  chitinous 
membrane,  tried  the  tincture  of  cochineal,  which  not  only  answered 
the  desired  purpose,  but  showed  itself  suitable  for  general  application 
wherever  it  is  required  to  stain  by  an  alcoholic  method  animal  tissues 
preserved  in  alcohol,  and  to  keep  the  preparations  flius  obtained  in  a 
resinous  medium. 

The  pulverized  cochineal  is  left  for  several  days  in  contact  with 
70  per  cent,  alcohol,  8-10  c.  cm.  to  a  gramme,  and  the  dark  red  liquid 
filtered.  The  object  to  he  stained  must  he  free  from  acid,  and  it  is  best 
to  lay  it  for  some  time  previously  in  fresh  alcohol  of  70  per  cent. 
Accordiug  to  the  intensity  required  and  the  nature  of  the  object,  the 
staining  takes  from  a  few  minutes  (infusoria,  marine  larva3,  &c.)  to  a  few 
days  (the  higher  Crustacea,  large  annelida,  young  cephalopoda,  organs 
of  vertebrata,  &c.). — The  subsequent  removal  of  the  staining  material 
which  is  not  fixed  in  the  tissue,  is  efiected  with  70  per  cent,  alcohol, 
and  takes  days  in  some  cases ;  it  can  never,  however,  be  continued  too 
long,  and  should  not  be  stopped  until  the  alcohol  takes  no  more  up. 

Ey  this  method,  assuming  that  the  object  has  been  properly  pre- 
served, a  very  precise  and  nearly  always  intense  nucleus  stain  is  obtained, 
*  '  Zoologischcr  Anzeiger,'  vol,  i.  p.  345. 


44 


NOTES    AND    MEMORANDA. 


and  in  by  far  the  majority  of  cases  this  is  not,  as  might  be  expected, 
coloured  red,  but  hfematoxylin.  Dr.  Mayer  expects  to  be  able  to  give  the 
explanation  hereafter  of  this  strange  phenomenon,  which,  however,  is  no 
detriment  to  the  process.  In  consequence  of  the  precision  and  tint  of 
the  stain,  the  preparations  are  for  the  most  part  not  to  be  distinguished 
from  those  obtained  with  hsematoxylin.  The  cochineal  tincture  also 
possesses,  in  common  with  the  well-known  alcoholic  hsematoxylin 
solution  of  Kleinenberg,  the  property  of  m.t  altering  the  tissues ;  on 
the  other  hand,  it  compares  favourably  with  it  in  the  simplicity  of  its 
production  and  apj^licatiun,  as  also  in  the  hold  taken  by  the  stain, 
which  in  this  respect  is  equal  to  carmine.  On  the  other  hand,  there 
is  the  defect  that  hitherto  the  attempt  to  stain  large  objects  sufficiently 
deeply  has  not  always  succeeded  ;  although  the  spinal  marrow  of 
the  calf,  in  pieces  one  centimetre  long  and  more,  could  be  stained  uni- 
formly and  deeply  enough. 

With  a  little  care,  permanent  overstaining  need  not  be  feared,  and 
can  be  removed  by  washing  in  acid  alcohol  (a  drop  of  muriatic  acid 
to  about  10  c.  cm.  of  70  per  cent,  alcohol). 

Prazmowski's  Heliostat. — The  woodcut  represents  this  instru- 
ment, which,  it  is  claimed,  is  much  less  complicated  and  cheaper  than 
any  existing  form,  and  more  easily  regulated.  The  drum  contains,  as 
usual,  the  clock  movement,  and  rotates  a  mirror  upon  its  axis  once  in 
forty-eight  hours.     On  the  circumference  of  the  drum  is  a  dial  with 


AfA^f/C.-,A 


the  hours  marked  upon  it,  the  spaces  between  each  hour  being  divided 
into  intervals  of  ten  minutes.  The  drum  rests  upon  supports,  which 
allow  it  to  be  inclined  in  such  a  manner  as  to  make  the  axis  of  the 
movement  coincide  with  the  direction  of  the  earth's  axis  at  the  place 
where  it  is  used. 

This  direction,  which  is  given  by  the  latitude  of  the  place,  need 
not  necessarily  be  known  to  the  operator,  the  adjustment  of  the  instru- 
ment with  respect  to  the  latitude  and  the  declination  of  the  sun  cor- 
responding to  the  day  of  the  year,  being  effected  at  once,  and,  so  to 
speak,    automatically.     The    aj^paratus    is  fixed   after  adjustment  in 


JOUR.  R.  MIC.    SO C.  VOL.11.  PI.  N. 


.,   \ 


^ 


^Jr^.^^-^ 


Fiq.  1' 


hp 


Fic 


r 


West  NewmomJfc  C"  lUJi. 


JMev/"    Sercsei-  orgajis     in    Insects. 


NOTES    AND    MEMORANDA.  45 

the  position  which  the  latitude  requires  by  a  screw,  which  presses 
upon  an  arm  marked  with  the  degrees  of  latitude  from  0°  to  70°. 

In  order  to  adjust  the  instrument,  it  is  placed  on  a  perfectly  hori- 
zontal sui'face ;  the  mirror  having  been  removed,  a  metallic  rule 
("forming  a  diameter  of  the  dial  plate)  is  fixed,  so  as  to  slide  easily  on 
the  axis  of  the  movement,  which  traverses  it  like  a  spindle.  This 
rule  is  terminated  at  its  extremities  by  two  perpendicular  pieces,  the 
shorter  one  being  pierced  with  a  small  hole,  the  other  marked  with 
a  division  representing  the  equation  of  time  and  the  declination  of  the 
sun  for  every  ten  days,  connected  by  a  continuous  line.  At  the  base 
of  the  shorter  upright  the  rule  has  an  aperture,  through  which  can 
be  seen  the  figures  on  the  dial.  To  set  the  apparatus  to  the  hour, 
the  rule  is  turned  round  the  axis  like  the  hand  of  a  watch  until  the 
exact  hour  and  fraction  of  the  hour  at  which  the  observation  is  made 
are  seen  in  the  aperture,  and  the  division  which  represents  it  on  the 
dial  coincides  with  an  index  placed  at  the  edge  of  the  aperture. 

For  final  adjustment  it  is  only  necessary  to  turn  the  instru- 
ment horizontally  on  the  table,  inclining  it  more  or  less  on  its  sujj- 
port,  until  a  ray  of  the  sun,  passing  through  the  hole  of  the  short 
upright,  produces  on  the  line  of  declinations  placed  on  the  opposite 
one,  a  small  image  of  the  sun  which  falls  exactly  on  the  point  corre- 
sponding to  the  day  of  the  year.  This  operation  takes  only  a  few 
moments,  and  is  extremely  easy. 

This  done,  the  instrument  is  adjusted  ;  the  screw  on  the  circle  of 
latitudes  is  tightened,  the  rule  taken  away,  and  the  stem  of  the  mirror 
is  slid  into  the  axis  of  the  movement.  The  mirror  can  be  turned  in- 
dependently, by  which  means  the  reflected  ray  may  be  directed  to  any 
azimuth.  A  fixed  horizontal  ray  is  thus  obtained,  which  may  be  further 
reflected  to  another  plane  mirror,  placed  at  some  distance  and  movable 
on  a  pedestal,  so  that  the  ray  may  be  directed  wherever  it  is  wanted. 

When  the  exact  time  is  not  known,  the  instrument  may  still  be 
adjusted  in  a  way  which  is  apj^roximately  correct,  by  adjusting  it  at 
about  noon.  It  may  also  be  adjusted  first  at  about  9  a.m.,  and  then 
about  3  P.M.  Each  time  this  is  done  a  line  is  drawn  on  the  table 
with  a  pencil,  the  foot  of  the  instrument  serving  as  a  rule.  These 
two  lines  form  an  angle  which  is  bisected,  and  along  the  line  which 
bisects  it  the  foot  of  the  instrument  is  placed.  The  latter  is  in  this 
way  adjusted  for  midday. 

The  clock  movement  has  an  anchor  scapement,  and  could  move  a 
much  larger  mirror.  A  small  dial  placed  on  the  drum  and  divided 
into  sixty  minutes,  on  which  a  minute-hand  moves,  allows  the  regu- 
larity of  the  motion  to  be  verified.  The  dial  of  hours  and  the  division 
for  the  days  are  enamelled,  and  consequently  proof  against  weather. 
The  whole  apparatus  is  very  portable. 

New  (Auditory)  Sense-organs  in  Insects. — Professor  Graber,  of 
Czernowitz,  announces  *  the  important  discovery  of  organs,  probably 
of  an  auditory  nature,  which  he  has  foimd,  one  in  the  antennae  of 
adult  Diptera,  the  other  in  a  larva  of  a  species  of  the  same  order. 

1.  Oioci/st-like  Organ  in  the  Antennce  of  Diptera  (Plate  IV.  Figs.  1 
la,  and  lb). — This  was  observed  in  Syrphiis  balteatus.    The  structure 
*  '  Arrhiv  f.  Mik.  Aimt.,'  vol.  xvi.  p.  oG. 


46  NOTES    AND    MEMORANDA. 

is  best  made  out  by  treating  the  fresh  antennae  with  1  per  cent,  osmic 
acid,  transferring  to  absolute  alcohol,  clarifying  with  kreosote,  and 
mounting  in  Canada  balsam. 

The  supposed  otocyst  is  a  brown,  thick-walled,  chitinous  sac, 
provided  with  hairs  internally,  having  a  diameter  of  0-027  mm.,  and 
lying  free  in  the  cavity  of  the  terminal  leaf-like  segment  of  the  an- 
tennfe,  towards  the  inner  side  of  the  joint  between  that  segment  and 
tlie  preceding  one.  Under  a  high  magnifying  power  the  chitinous 
wall  of  the  sac  is  seen  to  be  covered  with  rounded  or  angular  areas, 
the  hair-plates,  which  are  about  "0044  mm.  in  diameter,  and  in  tbo 
centre  of  each  of  which  is  a  dei)ression,  the  Jiair-jnf,  giving  attach- 
ment to  one  of  the  auditory  hairs,  which  project  in  a  radial  direction 
towards  the  centre  of  the  sac.  These  hairs  are  about  two-thirds  of  the 
radius  of  the  sac  in  length  and  '0009  mm,  in  diameter  at  the  base, 
where  they  are  somewhat  swollen.  They  contain  a  distinct  lumen. 
Running  through  the  wall  of  the  capsule  are  fine  pores  corresponding 
to  the  hairs.  The  chitinous  capsule  is  surrounded  by  a  layer  of 
columnar  eiiithelial  cells,  each  of  which  corresponds  to  one  of  the 
hair-plates,  and  the  whole  epithelial  sac  thus  constituted  is  again  sur- 
rounded by  a  delicate  tunica  propria. 

The  first  and  second  segments  of  the  antennpe  bear  only  isolated, 
scattered,  almost  spiny  hairs,  but  the  terminal  segment  has  a  regular 
and  dense  covering  of  two  kinds  of  appendages — true  covering  hairs 
formed  by , elevations  of  the  cuticula,  and  articulated  hairs  agreeing 
generally  with  those  of  the  other  segments.  The  antennary  nerve 
comes  direct  from  the  brain,  and  first  branches  when  within  the  basal 
segment.  A  quantity  of  fine  filaments  are  given  off  in  the  second 
segment,  and  go  principally  to  the  outer  spiny  hairs,  swelling  out  at 
their  roots  into  spindle-shaped  ganglia.  The  other  hairs  of  the  first 
and  second  segments  receive  their  nerves  directly  from  the  principal 
stem.  Between  the  second  and  third  segments  the  nerve  makes  an 
S-shaped  bend,  and,  passing  through  the  aperture  in  the  joint-mem- 
brane, divides  into  filaments  as  in  the  second  segment.  A  large  braucli 
is  seen  to  pass  direct  to  the  capsule,  but  the  connection  of  its  fibres  with 
the  epithelial  cells,  although  very  probable,  has  not  been  made  out. 

An  essentially  similar  structure  is  met  with  in  the  antennte  of 
Sicus  ferrugineus,  and  in  that  of  a  species  of  Helomyza ;  in  the  latter 
case  there  is  a  dark-edged  globular  structure,  which  Graber  considers 
to  be  the  sac  of  the  otolith,  and  suggests  that  the  otolith  itself,  of  which 
nothing  was  to  be  seen,  was  probably  dissolved  out  by  the  kreosote. 

Exact  physiological  observations  are,  of  course,  required,  before 
the  auditory  nature  of  their  structure  can  be  considered  as  certain ; 
but  Graber  mentions  Paasch's  observations  that  flies  when  startled  by 
a  sudden  noise  raise  the  third  joint  of  the  antennre,  as  if  "  pricking  up 
their  ears." 

It  is  also  requisite  to  know  something  of  the  development  of  the 
organ,  as  to  whether  it  is  formed  as  an  invagination  of  tho  inte- 
gument, and  also  of  its  distribution  in  Tracheata  generally.  With 
regard  to  the  latter  point,  Graber  states  that  he  has  found  it  in  many 
members  of  the  sub-order  Brachycera,  but  not  in  either  of  the  families 
Muscidoi  or  Tabanidce. 


NOTES    AND    MEMORANDA.  47 

Professor  Graber  expresses  his  doubt  as  to  the  auditory  nature  of 
the  structure  discovered  by  Leydig  in  the  halteres  of  certain  Diptera, 
and  also  dissents  from  tlie  views  of  the  same  authority  as  to  the 
olfactory  functions  of  the  special  rod-like  appendages  found  by  him 
on  the  antennae  of  many  Arthropods. 

Plate  IV.  Fig.   1. — -Eight  antenna  of  SyijyJms  halfeatus,  Deg.  (in 
optical  section).    I.,  II.,  III.,  the  three  segments  ;  St,  Integument 
of  epicranium  ;  N,  Antennary  nerve  ;  n',  n^,  7?-ni  aud  n,y,  its  first, 
second,  third,  and  fourth  branches ;  m,  m^,  Muscles  of  the  basal 
segment ;    Tr,    Trachea ;     tr,    its    vesicular   dilatation    in    the 
terminal  segment ;  ga,  Ganglia  at  the  base  of  the  articulated 
hairs  ;    g,  Joint  between  the  second  and  thii-d  segments ;    O, 
Opening    in   the   same,   through   which    the   antennary  nerve 
passes ;    gc,  Auditory  sac  surrounded    by  its   epithelium   and 
tunica  propria ;    a,  Wall  of    the    terminal    segment,  with   the 
investing   liairs  and  the  roots  of  the  articulated  hairs.     Am- 
plification iy^  Zeiss  Immers.  L. 
Fig.  1  a. — The  otocyst  (in  optical  section).     /J/,  Auditory  hairs ; 
hp.  Hair-plates ;  hpo.  Pore-canals  in  the  wall  of  the  chitinous 
capsule  corresponding  to  the  auditory  hairs  ;  Z,  Epithelial  cells 
of  the  auditory  sac ;  tp^  Tunica  proj)ria.      Amplification  ^—~- 
Zeiss  Immers.  L. 
Fig.  1  h. — The  chitinous  capsule  of  the  otocyst  (surface  view). 
w.  Wall ;  Tip,  Hair-plate  ;  li,  Root  of  the  auditory  hair  ;  hg,  Hair- 
pit  ;  fu,  Furrow  between  the  hair-plates.     Amplification   -^-^-^ 
Zeiss  Immers.  L. 
2.  New  Organ  in  the  Larva  of  a  Fly  (Plate  IV.  Fig.  3). — In  this 
case  the  main  structure  was  made  out  by  simply  placing  the  trans- 
parent maggot  under  the  compressorium.     The  organ  in  question  is 
situated  in  the  middle  line  of  the  dorsal  side  of  the  body,  immediately 
posterior  to  the  line  of  junction  between  the  ninth  and  tenth  segments. 
It  is  a  pear-shaped  sac,  0  •  3  mm.  in  length,  with  its  narrow  posterior 
end  produced  into  a  fine  tube.     It  seems  probable  that  tube  and  sac 
together  are  formed  as  an  invagination  of  the  external  surface. 

The  sac  and  tube  are  made  of  a  layer  of  epithelial  cells,  covered 
externally  by  a  tunica  propria,  and  lined  within  by  a  chitinous 
cuticle  which  bounds  their  lumen.  Within  the  sac  are  contained  four 
pairs  of  black  opaque  bodies  of  an  irregularly  rounded  form,  and  sus- 
pended by  hollow  stalks.  The  first  two  pairs  are  of  about  equal  size, 
being  0  •  03  mm.  in  diameter.  The  length  of  the  stalk  is  0  •  026  mm., 
and  its  breadth  at  the  point  O'OOIS.  The  third  and  fourth  pairs  are 
smaller,  and  are  only  0' 02  mm.  Probably  the  bodies  themselves  are 
also  hollow,  and  have  very  thick,  strongly  chitinized  walls,  but  their 
exact  structure  could  not  be  made  out,  as  they  remained  perfectly 
opaque  even  after  treatment  with  potash.  The  most  anterior  pair  of 
these  bodies  are  attached,  like  berries,  to  the  front  wall  of  the  sac; 
immediately  behind  tliem  is  a  chitinous  partition  separating  this 
anterior  segment  of  the  sac  from  the  remainder.  The  second  pair 
are  not  attached  directly  to  this  partition,  but  to  the  front  wall  of  a 
special  cellulose  capsule  (Binucnsack),  quite  separate  from  the  true 


48 


NOTES    AND    MEMORANDA. 


lining  of  the  sac,  closed  anteriorly,  but  merely  constricted  behind. 
Similarly  the  third  and  fourth  pairs  of  bodies,  which  are  in  close 
contact  with  one  another,  are  connected  to  the  front  wall  of  another  sac, 
the  anterior  closed  end  of  which  fits  into  the  neck  of  the  former,  while 
its  own  neck  extends  nearly  to  the  apex  of  the  main  sac.  Probably 
these  capsules  are  outpushings  of  the  chitinous  lining  of  the  main  sac. 
It  will  be  seen  that  there  are  thus  formed  three  capsules,  the 
actual  lining  of  the  sac  and  the  two  "  Binnensiicke,"  which  enclose 
one  another  like  the  coats  of  an  onion,  so  that  while  the  first  pair  of 
stalked  bodies  has  only  one  layer  of  chitinfe  outside  it,  the  second  pair 
has  two,  and  the  third  and  fourth  pairs  three. 

The  author,  "  proceeding  by  the  process  of  elimination,"  points  out 
that  the  organ  must  be  either  a  gland  or  a  sense-organ,  and  after 
going  over  the  arguments  for  and  against,  comes  to  the  conclusion 
that  it  cannot  be  a  gland ;  and,  further,  that  partly  from  its  position 
and  partly  from  its  structure  it  cannot  be  intended  for  touch,  smell, 
taste,  or  vision,  and  must  therefore  be  a  true  auditory  sac.  The 
stalked  bodies  he  considers  to  be  otoliths,  acting  from  their  mode 
of  attachment  like  the  clapper  of  a  bell. 

Plate  IV.  Fig.  2. — The  dipterous  larva — natural  size — showing 

the  position  (x)  of  the  supposed  auditory  organ. 
Fig.  2  a. — The  organ,  isolated.   K,  Fundus  of  the  sac  ;  Sp,  its  apex; 
ep,  Ke,  its   epithelium ;   Ca,  Chitinous  sac ;   s^,  s^,  S3,  its  three 
internal  capsules  ("  Binnensacke")  ;    e,  constriction  in  the  neck 
of  the  second  of  these  ;  st,  Stalked  bodies  ;  m,  Muscles  ;  lij,  n^, 
First  and  second  nerves ;    ga,  Ganglionic  swelling  on  the  first 
of  these ;  n,  branch  of  the  second  ;  r,  Tubular  prolongation  of 
the  sac.     Amj)lification  ^^  Zeiss  Immers.  L. 
At   the   end   of    his   paper    Graber   gives   the   following   useful 
diagram,  showing  in   a  tabular  form  the  various  forms  of  auditory 
organs  occurring  in  the  animal  kingdom. 

Chief  Forms  of  Auditory  Organ. 


Elementary  Auditonj  Organ. 

Isolated  auditory  cells  and 

auditory  hairs. 

Lower  animals  (?). 

Crustacea. 

Insects  (?). 


Sac-like  Auditory  Organ, 
or  Cystic  Form. 


Tympanic  Form  (with 
auditory  rods). 

Orthoptera. 


Wall  consisting  of  cells  only. 

Gymnotocysts. 


Wall  with  a  chitinous  cuticle. 

Chitinotocysts. 


With  ciliated  cells. 

Ciliotocysts. 

A-       1 

Mono-  >lithophorous. 
Poly-  ) 

Ccelenterata  (?). 
Vermes. 
Mollusca. 
Vertebrata. 


Cells  without  cilia. 

Non- ciliated 

gymnotocysts. 

rolylithoiDhorous, 

Ptychoptera. 

With  rosette-like 

central  organ. 

Larva  of  Corethra 

and 

ChironomusC?). 


With  hairs. 

Piliotocynts. 

A-       1 

Mono-  >litliophorous. 
Poly-  J 

Crustacea. 
Insecta 

(antennary 
otocysts). 


Without  hairs. 

Apilose 
chitinotocysts. 

With  stalked 
otoliths  (?). 

riy  larva. 


NOTES   AND   MEMORANDA.  49 

The  Fibrillae  of  Filifera. — Oscar  Schmidt  has  recently  given  an 
account  *  of  the  curious  fibrillas  found  among  the  ordinary  horny 
fibres  of  the  sponge  Filifera.  These  bodies  occur  in  the  form  of  fine 
knobbed  fibres,  agreeing  in  chemical  and  microscopical  character 
with  the  fibres  of  Euspongia,  except  for  the  fact  that  a  cell-like  body 
is  regularly  developed  in  the  knob,  when  the  latter  separates  from  the 
softer  axial  portion  of  the  fibrilla.  Less  frequently  the  formation  and 
subsequent  separation  of  one  or  two  similar  bodies  occurs  in  the 
axial  portion  itself.     Division  of  the  fibrillfe  also  takes  place. 

Kolliker  doubted  whether  the  fibrillse  might  not  be  parasites  ;  but 
this  conjecture  is  erroneous,  as  also  is  the  former  opinion  of  Oscar 
Schmidt  himself,  that  they  arise  from  the  ordinary  coarse  fibres  of  the 
horny  skeleton.  The  difliculties  attending  their  isolation  are  so  great, 
that  the  author  has  only  recently  succeeded  in  accomjjlishing  it,  thus 
making  out  for  the  first  time  their  true  form.  He  states  that  the 
perfect  fibres  are  knobbed  at  both  ends  and  resemble  children's 
skipping-ropes.  Their  dimensions  are  subject  to  remarkable  fluctu- 
ations, the  long  diameter  of  one  and  the  same  knob  varying  from 
O'OOS  to  0*01  mm.,  and  the  length  of  a  carefully  isolated  fibre  from 
1  •  4  to  1*6  mm. 

The  Ovule. — M.  E.  Warming,  the  Danish  naturalist,  has  pub- 
lished in  Danish  the  i-esults  of  his  investigations  on  the  ovule.  A 
translation  in  French  appears  in  the  '  Annales  des  Sciences  Natu- 
relles '  (occupying  more  than  70  pp.),  from  which  the  follow^ing 
(being  the  author's  ''  Conclusion  ")  is  extracted  : — 

I.  Few  organs  have  been  the  object  of  such  varied  interpretations 
as  the  ovule.  Some  (Schleiden,  St.  Hilaire,  A.  Braun,  Strasburger, 
Wigaud,  Eichler,  &c.)  consider  it  as  a  bud,  of  which  each  integu- 
ment is  an  independent  leaf,  or  a  disk  (Schacht,  Endlicher,  Unger) ; 
the  others  as  an  organ  of  a  foliar  nature,  in  which  the  funicle  alone 
(Eossman),  or  the  funicle  and  the  integuments,  is  an  ovular  leaflet  or 
a  lube  of  a  leaf.  From  this  point  opinions  diverge.  According  to 
some,  the  nucleus  is  a  part,  a  tooth  of  this  leaf  (Reissek) ;  according 
to  others,  a  new  creation.  In  the  latter  case  it  is  sometimes  regarded 
as  a  bud  (Caspary,  Rossman),  sometimes  as  a  metablast,  and  latterly 
as  the  homologue  of  a  sjDorangium  (Brongniart,  Cramer,  Tieghem, 
Celakovsky).  I  agree  with  the  latter  opinion.  There  are  also  some 
observers  who  consider  that  the  ovule  may  have  a  different  significa- 
tion in  one  plant  and  another,  relying  on  its  position  either  on  the 
summit  of  the  axis  or  on  a  leaf.  I  was  formerly  of  the  same  opinion, 
but,  thanks  to  the  excellent  reasoning  of  M.  Celakovsky,  I  have  recog- 
nized that  the  morphological  signification  of  an  organ  does  not 
dejjend  absolutely  on  its  position.  Considering  the  jjerfect  concord- 
ance in  the  structure  of  all  the  ovules  of  the  Angiosperms,  even  those 
inserted  on  the  most  diverse  organs,  this  opinion  is  inadmissible  ;  and 
comj)arative  study  has  done  complete  justice  to  it  in  negativing  the 
idea  that  the  organ  which  is  the  sporangium  in  the  Cryptogams,  may 
become  a  bud  in  the  Phanerogams. 

It  has  been  desired  to  invoke  the  law  of  shifting,  according  to 
*  '  Zeitbch.  f.  wiss.  Zool.,'  vol.  xxx.  p.  661. 

VOL.    II.  E 


50  NOTES    AND    MEMORANDA. 

whicli  the  same  physiological  functions  can  be  exercised  by  organs 
which  are  very  different  morphologically,  and  it  has  hence  been  con- 
cluded that  that  must  be  true  for  the  ovule — though  it  may  be  possible, 
it  does  not  necessarily  follow  that  it  is  so.  I  pass  by  this  illogical 
reasoning,  therefore,  until  there  has  been  discovered  a  well-estab- 
lished fact  showing  that  the  functions  of  the  ovule  are  fulfilled  by 
an  organ  which  cannot  be  assimilated  to  a  sporangium.  A.  Brauu 
recognizes  "  that  an  organ  analogous  from  a  phylogenetic  j^oint 
of  view  to  a  sporangium  developed  on  a  leaf,  and  to  the  pollen  sac 
of  the  staminal  leaf,  should  be  considered  as  an  excrescence  of  the 
carpel ;"  but  he  adds  that  "  in  its  ulterior  development  it  may  be  ele- 
vated to  the  dignity  of  a  vegetative  point  j^roducing  some  leaves  in  the 
form  of  sheaths  destined  to  protect  the  organ  of  reproduction  which  is 
formed  on  the  vegetative  summit  itself."  In  other  words,  that  an 
organ  of  any  morphological  nature  whatever  may  be  transformed  into 
another  of  superior  dignity.  These  considerations  are  so  wanting  iu 
foundation,  they  are  so  opposed  to  observed  facts,  that  I  can  see  nothing 
else  on  the  part  of  the  celebrated  mori:)hologist  than  an  attempt  to 
sustain,  notwithstanding  its  contradictions,  a  favourite  theory,  but  one 
nevertheless  that  cannot  be  supj^orted. 

II.  I  sum  up  briefly  my  results  and  my  arguments,  in  comparing 
the  different  ovular  theories. 

The  theory  according  to  which  the  ovule  is  a  bud  has  found  support 
in  the  terminal  position  of  a  great  many  ovules,  which  makes  them 
appear  as  the  direct  continuation  of  the  axis.  But  M.  Celakovsky  has 
shown  that  the  terminal  j)osition  (or  generally  any  position  whatever 
of  an  organ)  cannot  demonstrate  its  morphological  value,  since  there 
exist,  for  example,  terminal  leaves.  He  has  j)roved  that  the  part  of  the 
pistil  which  carries  the  ovule  is  everywhere  of  a  foliar  nature,  even  in 
the  case  of  a  central  free  placenta.  In  this  he  is  of  the  same  opinion 
as  M.  Van  Tieghem,  who  has  pursued  an  entirely  difterent  line.  I 
agree  in  this  opinion,  and  I  have  endeavoured  to  show  that  the  history 
of  development,  in  general  very  ineffective  iu  similar  questions,  teaches 
us  that  the  placenta  or  the  terminal  ovule  in  certain  cases  is  a  new 
creation  on  the  summit  of  the  axis.  Amongst  the  Gymnosperms  we 
find  at  first  in  the  Cycadacese  true  carpellary  leaves,  and  it  has  been 
established  that  the  scales  which  bear  the  ovules  in  the  Abietinese  are 
of  a  leafy  nature,  even  when  the  scale  cannot  be  interpreted  as  the 
fertile  ventral  part  of  the  protecting  scale,  as  I  have  mentioned  hypo- 
thetically  in  my  work  on  the  Cycadaceie.  The  concordances  in  the 
structure  and  anatomy  enable  us  to  admit  that  it  is  true  also  for  the 
other  Conifers  (with  non-terminal  ovule).  For  the  Gingl-o  the  ovular 
organ  situated  in  the  axil  of  the  scales  of  the  bud  or  of  the  leaves, 
must  be  considered  as  being  comj)osed  of  two  leaves  joined  together, 
belonging  to  an  axillary  bud,  like  the  needle  of  Sciadopitijs.  The  two 
parts  are  even  placed  in  the  same  manner,  the  physiologically  lower 
face  being  turned  towards  the  principal  axis.  Amongst  the  Cupres- 
sinesB  and  other  Conifers  with  scales  apparently  simj^le,  the  union  of 
two  organs  must  be  admitted,  with  MM.  Van  Tieghem  and  Strasburger. 
I  admit  that  I  am  not  able  to  apprehend  in  all  its  details  the  disposi- 


NOTES    AND    MEMORANDA.  51 

tiou  of  the  ovule  in  Taxus,  but  I  will  willingly  take  it  for  a  terminal 
leaflet  with  a  monangian  sorus  equally  terminal. 

The  carpels  of  the  Angiosperms  are  distinguished  from  those  of 
the  Gymnosperms  in  that  the  former  bear  the  ovules  on  the  superior 
face,  the  others  on  the  inferior  when  the  ovules  are  not  exactly 
marginal.  The  same  observation  applies  to  the  stamens,  those  of  the 
Conifers  and  the  Cycadaceae  carry  the  pollen  sacs  on  the  inferior  face, 
those  of  the  Angiosj^erms  on  the  superior  face  or  at  the  side. 

M.  Celakovsky  compai'es  the  stamen  of  the  Angiosperms  to  the 
leaf  of  the  Ophioglossum.  Assuredly  there  is  here  a  very  ingenious 
comparison,  but  one  which  can  only  be  placed  in  the  category  of  bold 
aud  somewhat  vague  hypotheses  founded  on  a  too  restricted  number 
of  observed  facts. 

The  terminal  position  of  the  ovule  does  not  prove  that  this  organ 
is  a  bud ;  on  the  contrary,  the  placentae  must  be  everywhere  phyllomes. 

The  mode  of  development  of  the  ovule,  especially  that  of  the 
Conifers,  should  tend  according  to  some  authors  to  its  being  considered 
a  bud.  It  is  impossible  to  have  confidence  in  the  history  of  develop- 
ment when  the  question  is  to  determine  the  morphological  nature  of 
an  organ.  It  everywhere  requires  a  correction.  M.  Strasburger 
has  allowed  himself  to  be  too  much  guided  by  preconceived  ideas 
in  the  interpretation  of  the  phenomena  of  development.  Moreover, 
I  have  shown  that  the  histogenesis  of  the  ovule,  as  he  has  described 
it,  is  not  correct,  especially  in  relation  to  the  development  of  the 
nucleus. 

MM.  Celakovsky  and  Cramer  have  shown  that  teratology  cannot 
be  invoked  to  prove  that  the  ovule  is  a  bud.  The  theory  of  Brong- 
niart  is  much  more  admissible.  In  the  first  place,  the  carpels  and 
the  placentas  are  phyllomes ;  that  being  so,  it  is  difficult  to  admit 
that  the  ovules  are  buds.  It  is  true  that  buds  may  grow  on  a  leaf, 
but  to  admit  that  the  ovules  are  similar  buds  developed  regularly  on 
a  carpellary  leaf  requires  reasons  of  great  weight.  Moreover,  the 
descending  progression  of  the  integuments  is  not  in  accord  with  this 
theory. 

Secondly,  the  teratological  cases  show  us  everywhere  the  ovule 
(funicle  and  integuments)  transformed  into  a  lobe  of  a  leaf  on  which 
the  nucleus  is  a  new  creation,  in  the  light  of  an  outgrowth :  this  fact  is 
confirmed  by  histogenesis.  I  may  recall  here  that  two  nuclei  have 
sometimes  been  observed  on  the  same  ovular  leaflet,  which  does  not 
agree  with  the  theory  of  Braun,  but  very  well  with  that  of  Brongniart. 

Thirdly,  the  development  of  the  nucleus  is  so  like  that  of  the  pollen 
sac  of  the  Angiosperms,  that  their  homology  cannot  be  doubted  : 
further,  the  pollen  sac  itself  is  the  homologue  of  the  sporangium  ; 
therefore  the  nucleus  must  be  compared  to  the  macrosporangium.  I 
do  not  know  why  it  should  be  given  the  name  of  "  sporocyst,"  which 
can  scarcely  be  applied  to  any  but  the  Marattiaceae,  for  M.  Strasburger 
has  not  yet  demonstrated  that  the  sporangia  of  the  Equisetaceae  and 
the  Lycopodiacefe  are  sporocysts.  This  name  could  better  be  given  to 
the  pollen  sacs  of  the  Angiosperms. 

The  sporangia  of  the  Cryptogams  all  grow  on  the  leaves.     The 

E  2 


52  NOTES    AND    MEMORANDA. 

comparison  of  the  nucleus  to  the  sporangium  and  to  the  pollen  sac, 
confirms  the  results  which  we  have  obtained  by  the  comjiarative  study 
of  the  carpel. 

The  insertion  of  the  nucleus  on  a  leaf  is  proved  for  the  Gymno- 
spei*ms  and  a  part  of  the  Conifers  ;  it  may  also  be  admitted  in  a 
general  way  for  the  other  part  of  this  family,  but  the  details  are  still 
unknown. 

The  Gymnosperms,  however,  differ  notably  from  the  Angiosperms 
in  several  points,  and  constitute  a  separate  branch  which  has  not  the 
same  origin.  The  following  are  some  of  the  differences  which  separate 
them :  the  forcing  down  of  the  female  sporangium  ;  the  origin  of  the 
integument  in  two  primordial  points  in  a  part  of  the  genera ;  the 
development  of  the  proembryo  and  the  embryo  ;  the  disposition  of  the 
pollen  sacs,  and  (in  part)  of  the  ovules  on  the  staminal  or  carpellary 
leaf. 

As  the  pollen  sacs,  wherever  their  position  has  been  clearly  recog- 
nized, are  borne  on  the  leaves ;  as  all  the  facts,  in  the  obscure  cases, 
seem  to  indicate  the  same  thing ;  as  that  is  true  for  the  ovule ;  as  the 
sporangia  of  the  Cryptogams,  the  common  and  primitive  form  of  the 
phanerogamous  reproductive  organs,  are  equally  developed  on  leaves, 
it  must  be  admitted  as  a  general  rule  that  the  reproductive  organs  of 
all  the  vascular  plants  are  borne  on  the  leaves,  and  that  morphologi- 
cally they  are  metablasts. 

I  shall  be  pleased  if  this  memoir  should  contribute  to  the  general 
acceptance  ere  long  of  the  theory  of  Brongniart,  the  only  true  and 
admissible  one — that  I  am  now  convinced  of  it  is  due  in  great  part  to 
the  ingenious  Slave  botanist,  Ladislao  Celakovsky.* 

Laboratory  for  Microscopic  Work. — In  the  Zoological  Laboratory 
at  Newport,  Ehode  Island,  U.S.,  recently  established  by  Professor 
Alexander  Agassiz,  the  tables  for  microscoj)ic  work  are  three-legged 
stands,  of  varying  height,  adapted  to  the  different  kinds  of  Micro- 
scopes in  use.  The  whole  of  the  northern  side  of  the  floor  upon 
which  the  work-tables  and  microscope-stands  are  placed,  is  sujiported 
upon  brick  piers  and  arches  independent  of  the  main  brick  walls  of 
the  building,  which  form  at  the  same  time  the  basement  of  the 
building.  The  rest  of  the  floor  is  supported  entirely  upon  the  outside 
walls  and  upon  columns  with  stretchers  extending  under  the  crown  of 
the  arches  reaching  to  the  northern  wall.  This  gives  to  the  micro- 
scopic work  the  great  advantage  of  complete  isolation  from  all 
disturbance  caused  by  walking  over  the  floor.  This  will  be  duly 
appreciated  by  those  who  have  worked  in  a  building  with  a  wooden 
floor,  where  every  step  caused  a  cessation  of  work  and  was  sure  to 
disturb  any  object  just  at  the  most  interesting  moment. f 

A  New  Micrometer. — Spider-line  micrometers,  or  micrometers  of 
fine  threads  of  platinum,  are  inconvenient  from  the  thickness  of  the 
threads,  from  their  expansion  or  contraction  under  thermic  or 
hygrometric  influences,  from  the  difficulty  of  fixing  them  parallel  to 

*  '  Ann.  tics  Se.  Nat.  (Bot.),'  6th  series,  vol.  v.  p.  250. 
t  '  Am.  Jour.  Sci.  aud  Arts,'  vol.  xvi.  p.  488. 


NOTES   AND    MEMORANDA.  53 

eacli  other  at  very  small  distances,  or  from  their  breaking  so  easily, 
and  the  difficulty  of  replacing  them  without  the  help  of  an  expert. 

In  a  micrometer  devised  by  M.  G.  Govi,*  the  threads  are  replaced 
by  the  two  edges  of  a  slit  made  in  a  very  thin  layer  of  silver,  gold, 
platinum,  or  other  metal  deposited  on  the  surface  of  a  glass  slide 
which  has  its  faces  perfectly  plane  and  parallel.  Such  metallic  coat- 
ings may  be  obtained  sufficiently  opaque  with  a  thickness  of  less  than 
a  hundred  thousandth  of  a  millimetre.  The  slit  is  made  by  a  steel 
tracer  so  lightly  as  not  to  touch  the  glass.  The  breadth  of  the  slit 
depends  on  the  fineness  of  the  tracer,  its  neatness  not  only  on  the 
shape  of  the  tracer,  but  also  on  the  thinness  of  the  metallic  layer. 
When  broad  slits  are  wanted  it  is  best  to  remove  the  metal  in  parallel 
furrows  rather  than  attempt  to  attain  the  same  result  by  a  larger 
tracer,  which  might  produce  slits  with  irregular  edges.  The  metallic 
layer  should  be  placed  on  the  side  whence  the  image  comes,  so  that 
the  rays  which  emanate  from  it,  and  the  light  which  grazes  the  edges 
of  the  slit,  may  have  to  traverse  the  same  thickness  of  glass  and 
undergo  the  same  modifications. 

In  consequence  of  the  extreme  thinness  of  the  metal  coating,  the 
strongest  eye-pieces  give  no  sensible  thickness  to  the  edges  of  the  slit. 
There  is  therefore  nothing  to  fear  from  the  eflPects  of  parallax  even 
when  the  micrometer  is  applied  to  images  placed  in  the  extremities  of 
the  field. 

There  should  always  be  a  portion  of  the  metallic  coating  removed 
normal  to  the  slit,  so  as  to  allow  the  observer  to  see  the  images 
when  they  appear  on  the  field  of  the  Microscope,  and  when  they  pass 
oif  between  the  edges  of  the  slit.  It  is  a  good  plan  to  remove  a  little 
less  than  half  the  opaque  coating,  leaving  intact  the  other  half  where 
the  slit  is.  It  is  equally  practicable  to  take  off  two  equal  bands  of 
metal  at  the  two  extremities  of  tiie  slit,  and  leave  only  the  central 
zone  in  the  field,  which  need  not  be  very  broad. 

If  a  number  of  slits  of  difterent  width  be  made  on  one  plate,  it  is 
possible  to  avoid  employing  several  micrometers. 

The  extreme  tenuity  of  the  metallic  coating,  its  opacity,  its 
rigidity,  and  the  fact  of  its  not  altering  under  considerable  thermo- 
metric  and  hygrometric  variations  ;  tlie  possibility  of  making  slits  as 
narrow  or  wide  as  desired ;  the  facility  of  substituting  different  slides 
in  the  same  frame,  are  advantages  in  this  micrometer  which  should, 
as  it  seems  to  me,  induce  observers  to  use  it  in  place  of  the  thread 
micrometer. 

"Cell-Soul  and  Cellular  Psychology-" — Professor  Haeckel  has 
recently  published  his  reply  to  the  address  on  "  The  Liberty  of 
Science  in  the  Modern  State,"  delivered  at  last  year's  meeting' 
of  the  German  Association,  by  Professor  Virchow.  He  states  that 
the  views  he  expressed  at  Munich  with  regard  to  tlie  soul  of  the 
cell,  i.  e.  "  that  we  must  ascribe  an  independent  soul-life  to  each 
organic  cell,"  are  but  the  natural  consequence  of  Virchow's  own 
teachings,  viz.  of  the  very  fertile  application  which  Virchow  made  of 

*  'Comptes  Rendus,'   vol.  Ixxxvii.  p.  557.     The  micrometer  as  described  is 
intended  more  especially  for  meteorological  observations. 


54  NOTES   AND    MESIORANDA. 

the  cell  theory  to  pathology.  He  then  proceeds  to  give  the  definition 
of  the  word  "soul"  according  to  both  philosophical  theories.  First 
according  to  the  monistic  or  realistic  theory  (i.  e.  that  organisms  have 
been  developed  naturally,  in  which  case  they  must  descend  from  the 
simplest  and  common  ancestral  forms),  and  then  according  to  the 
dualistic  or  spiritualistic  theory  (i.  e.  that  the  different  species  of 
organisms  have  originated  independently  of  one  another,  in  which 
case  they  can  only  have  been  created  in  a  supernatural  way — by  a 
miracle),  he  compares  the  simj^licity  of  the  former  with  the  mystery 
and  irrationality  of  the  other,  and  shows  the  futility  of  Virchow's  view 
that  we  cannot  find  psychic  phenomena  in  the  lower  animals. 
"  Volition  and  sensation,  the  most  general  and  most  indubitable 
qualities  of  all  mental  life,  cannot  be  overlooked  in  the  lower  animals. 
Indeed,  with  most  Infusoria,  particularly  with  Ciliata,  independent 
motion  and  conscious  sensation  (of  pressure,  heat,  light,  &c.)  are  so 
very  evident,  that  one  of  their  most  patient  observers,  Ehrenberg, 
maintained  up  to  his  death  that  all  Infusoria  must  have  nerves  and 
muscles,  organs  of  sense  and  of  mind  (Seelenorgane),  just  like  all 
higher  animals. 

Now  it  is  known  that  the  enormous  progress  which  science  has 
recently  made  in  the  natural  history  of  these  low  organisms  has 
reached  its  climax  in  the  maxim  that  they  are  unicellidar  (a  maxim 
which  Siebold  pronounced  thirty  years  ago,  but  which  has  been 
proved  with  certainty  only  recently)  ;  therefore  in  the  Infusoria  a 
single  cell  performs  all  the  different  functions  of  life,  including  the 
mental  functions,  which  in  the  HydrcB  and  Spongice  are  divided 
amongst  the  cells  of  the  two  germinal  lobes,  and  in  all  higher 
animals  amongst  those  of  the  various  tissues,  organs,  and  apparatus 
of  a  complicated  organism.  .  .  .  By  the  same  right  by  which  we 
ascribe  an  independent  '  soul '  to  these  unicellular  Infusoria,  we  must 
ascribe  one  to  all  other  cells,  because  their  most  important  active 
substance,  the  protoplasm,  shows  everywhere  the  same  psychic 
properties  of  sensitiveness  (sensation)  and  movability  (volition).  The 
difference  in  the  higher  organisms  is  only  that  there  the  numerous 
single  cells  give  up  their  individual  independence,  and  like  good 
state-citizens,  subordinate  themselves  to  the  '  state-soul '  which  repre- 
sents the  unity  of  will  and  sensation  in  the  '  cell-association.'  We 
must  distinguish  between  the  central  soul  of  the  total  polycellular 
organism  or  the  '  personal  soul '  and  the  separate  elementary  souls  of 
the  single  cells,  or  '  cell-souls."  This  maxim  is  excellently  illustrated 
by  the  interesting  group  of  Siplionopliora.  There  is  no  doubt  that  the 
whole  Siphonophora-st&te  has  a  very  determined  and  uniform  (einheitlich) 
will  and  sensation  ;  yet  each  one  of  the  single  individuals  which 
compose  this  state  (or  Cormus^  has  its  separate  j^ersonal  will  and 
sensation.  Indeed,  each  one  of  these  is  originally  a  separate  Medusa, 
and  the  '  individual '  Siphonophor a-state  has  resulted  only  by  association 
and  division  of  labour  of  this  united  society  of  Medusae.  Next  to  the 
unicellular  Infusoria  no  phenomenon  affords  such  ample  and  im- 
mediate proof  for  the  truth  of  our  cellular-psychology  than  the  fact 
that  the  human  ovnm,  like  the  ovum  of  all  other  animals,  is  a  simple 


NOTES    AND    MEMORANDA.  55 

and  single  cell.  According  to  oui*  monistic  conception  of  tlie  cell- 
soul,  we  must  suppose  that  the  fertilized  ovum  already  possesses 
virtually  those  psychic  properties  which  in  the  particular  mixture  of 
parental  peculiarities  (i.  e.  those  of  mother  and  father)  characterize 
the  individual  soul  of  the  new  being.  In  the  course  of  the  develop- 
ment of  the  ovum  the  cell-soul  of  course  develops  itself  simul- 
taneously with  its  material  substratum,  and  becomes  apparent  actually 
when  the  child  is  born.  According  to  Virchow's  dualistic  conception 
of  the  '  Psyche,'  we  must  suppose,  on  the  contrary,  that  this  im- 
material being  enters  the  soulless  germ  at  some  period  of  embryonal 
development  (perhaps  when  the  spinal  tube  separates  from  the  germinal 
lobe?).  Of  course  in  this  way  the  pure  miracle  is  complete,  and  the 
natural  and  uninterrupted  continuity  of  deielopment  is  superfluous."  * 

Post-embryonic  Formation  of  Appendages  in  Insects. — H.  Dewitz 
was  led  by  Darwin's  remarks  in  the  '  Origin  of  Species,'  on  the 
difficulty  offered  to  the  doctrine  of  natural  selection  by  the  neuters  of 
^insects  living  in  communities,  to  make  some  researches  on  this 
subject,  the  results  of  which  he  sums  up  as  follows:  |  — 

The  workers  of  ants  possess  very  small  wing-disks,  situated 
precisely  as  in  winged  insects,  and  undergoing  subsequent  retro- 
gressive metamorphosis.  A  figure  is  given,  showing  a  rudiment  of 
the  posterior  wing  in  an  adult  worker. 

The  thoracic  appendages  of  ants  first  appear  as  a  disk-shaped 
thickening  of  the  hypodcrmis,  which  becomes  separated  into  a 
central  portion,  the  rudiment  of  the  leg  or  wing,  and  a  surrounding' 
membrane  ;  an  aperture,  opening  outwards,  being  left  in  the  latter. 
The  membrane  grows  as  a  sack-  or  pocket-shaped  invagination,  into 
the  interior  of  the  body,  and  when  metamorphosis  takes  place,  the 
original  aperture  is  enlarged  to  allow  of  the  extrusion  of  the  limb. 

The  young  thoracic  appendages  of  ants  and  bees  secrete  a 
chitinous  cuticle  during  the  larval  condition.  The  difference  betsveen 
the  limbs,  formed  during  post-embryonic  life,  of  Holomctabola  and 
of  Ametabola,  does  not  consist  in  the  formation  or  non-formation  of 
this  cuticle,  but  in  the  fact  that  in  Holometahola  the  newly  formed 
appendages  lie  for  the  most  part  concealed  in  invaginations  of  the 
hypoderm,  making  their  appearance  first  iu  the  pupa  sta«e,  while 
in  Ametahola  they  are  visible  from  the  first. 

The  formation  of  the  wings  of  LepidojJtera,  and,  in  the  author's 
opinion,  that  of  the  appendages  of  all  insects,  takes  place  from  the 
hypoderm,  although  probably  their  internal  differentiation  is  always 
brought  about  by  the  penetration  into  them  of  nerves,  trache®,  &c. 

The  main  difference  between  the  females  and  workers  of  ants  is 
not  produced  as  in  bees,  by  a  different  treatment  of  the  eggs  or  ]arv» 
on  the  part  of  the  adult  workers,  but  the  future  fate  of  the  e^^g  is 
settled  while  still  in  the  body  of  the  mother. 

The  "Weber  Slide. — The  well-known  live-box  or  animalcule  cawe 
serves  the  purpose  of  preserving  and  exhibiting  living  objects  very 

*  'Nature,'  vol.  xix.  p.  113. 

t  'Zeitsch.  f.  wiss.  Zool.,'  vol.  xxx.  (Suppl.),  p.  78. 


56  NOTES    AND    MEMORANDA. 

well,  but  it  does  not  entirely  prevent  the  evaporation  of  the  liquid  in 
whicli  tlic  objects  are  contained.  The  ordinary  concave  slide,  though 
better  than  a  plain  slip  of  glass,  does  not  fulfil  all  the  requirements ; 
and  with  such  a  slide  it  is  difficult  to  keep  the  object  in  focus,  except 
with  very  low  powers. 

To  obviate  these  difficulties,  Mr,  Weber  has  reversed  the  form  of 
the  cell,  and  forms  his  slide  as  shown  in  the  accompanying  engra- 
ving, where  A  is  the  convex  bottom  of  the  cell,  and  B  the  thin  glass 


cover,  a  drop  of  water  being  held  between  them  by  capillary  attrac- 
tion. When  the  cover  is  cemented  down  by  means  of  a  little  water- 
proof cement,  the  water  cannot  evaporate,  and  the  whole  arrangement 
forms  an  air-tight  aquarium  on  a  minute  scale.  The  open  space  forms 
a  chamber  which  retains  a  supj^ly  of  air,  and  if  the  animal  and 
vegetable  life  are  properly  balanced,  life  may  exist  in  one  of  these 
slides  for  weeks. 

In  the  woodcut,  which  shows  the  slide,  the  thickness  of  the  slide, 
&c.,  is  magnified  about  four  times.* 

The  form  of  the  crystalline  Cones  in  the  Arthropod  Eye. — Oscar 
Schmidt  contributes  a  paj)er  on  this  subject  to  the  '  Zeitschrift  f.  wiss. 
Zool.'  t  He  commences  by  a  short  statement  of  the  views  of  Exner 
and  of  Grenadier,  the  latest  writers  on  the  subject,  and  remarks  that 
both  they  and  all  their  predecessors  consider  each  visual  cone  to  be 
perpendicular  to  the  corresponding  corneal  surface,  so  that  only  those 
rays  of  light  which  strike  the  cornea  at  right  angles  are  of  any  avail 
in  the  formation  of  an  image,  being  able  to  pass  unbroken  and  unre- 
flected  to  the  apex  of  the  cone. 

The  author  then  proceeds  to  describe  the  visual  rods  in  the  amphi- 
podous  genus  Phronima.  This  animal  possesses  two  pair  of  eyes : 
lateral  eyes  (Seiten-augen),  situated  in  the  usual  position  at  the  sides 
of  the  anterior  part  of  the  head,  and  in  the  same  transverse  section 
as  the  brain  ;  and  frontal  eyes  (Stirn-Scheitel-Augen),  placed  at  the 
vertex  of  the  head,  very  far  posterior  to  the  brain.  l'"ach  eye  is  supplied 
with  nerve-fibres  from  the  optic  ganglion,  which  fibres  enter  a  mass 
of  pigment  of  a  brown  or  yellow^  colour  visible  with  the  naked  eye,  and 
become  surrounded  with  a  sheath  closely  adherent  to  the  pigment.  The 
pigmented  body  of  the  lateral  eye  is  comj)aratively  small,  that  of  the 
frontal  eye  largeand  spindle-shaj)ed;  withit  are  connected, in  each  case, 
the  proximal  ends  of  the  visual  rods  or  crystalline  cones,  the  distal  ends 
of  which  abut  against  the  external  surface.  In  the  lateral  eye  no  two 
cones  are  found  alike  :  those  of  the  central  portion  of  the  organ 
approach  most  nearly  to  the  conical  form,  and  even  they  are  not  really 
conical,  having  an  almost  globular  distal  extremity  or  head,  and  a 
spindle-shaped  swelling  near  the  proximal  end,  where  they  become  con- 
tinuous with  a  nerve-fibre.     In  the  frontal  eye  the  visual  rods  are 

*  '  American  Journal  of  Microscoi^y,'  vol.  iii.  p.  253. 
t  '  Zeitsch.  f,  wiss.  Zool.,'  vol.  xxx.  (Suppl.),  p-  1- 


NOTES    AND   MEMORANDA.  57 

even  less  truly  conical ;  eacli  consists  of  a  conical  or  rather  globular 
head,  a  long  central  filamentous  portion,  and  a  proximal  spiudle-shaj)ed 
portion.  There  is  no  cornea  in  either  the  lateral  or  the  frontal  eye, 
but  the  distal  end  of  each  cone  comes  into  relation  at  the  surface  with 
a  double  cell,  containing  two  (Semper's)  nuclei.  These  double  cells 
do  not  fit  closely  to  one  another,  but  leave  triangular  interspaces  :  the 
boundary  wall  between  the  two  halves  of  which  they  are  composed 
penetrates  into  a  very  evident  cleft,  marking  the  division  of  the  cone 
into  two  longitudinal  segments.  Schmidt's  observations  give  no 
support  to  Pagenstecher's  view  that  this  sej^aration  of  the  cone  into 
two  longitudinal  moieties  is  an  evidence  of  multiplication  by  division. 

But  perhaps  the  most  important  observation  on  these  cones  is 
that  in  hardly  a  single  case  is  the  axis  of  the  visual  rod  at  right 
augles  to  the  external  or  corneal  surface,  so  that  Miiller's  theory  of 
mosaic  vision  is  here  quite  inapplicable,  since  there  is  neither  the 
straightness  of  the  refracting  bodies,  nor  the  contrivance  for  absorp- 
tion of  lateral  rays  required  by  that  view  of  the  action  of  the  so- 
called  compound  eye.  The  author  considers  that  the  eyes  o{  Phronima 
are  mere  makeshifts  for  image-forming  organs,  and  that  they  servo 
only  to  distinguish  different  degrees  of  light  and  colour. 

Observations  on  the  visual  rods  of  other  Crustacea  showed  that  in 
Palcemon  many  of  the  cones  are  straight,  but  that  those  at  the  periphery 
of  the  organ  are  oblique  to  the  corneal  facets,  their  proximal  segments 
being  strongly  bent.  In  Palinurus  this  flexure  sometimes  amounts  to 
90°.  In  the  lobster  the  rods  are  very  irregular,  hardly  two  being 
alike :  their  j^roximal  segments  show  the  greatest  amount  of  vari- 
ability as  to  size  and  degree  of  flexures,  and  have  no  resemblance  at  all 
to  image-forming  bodies. 

The  only  insect  examined  by  the  author  is  Dytiscus  marginalis ;  in 
it,  as  in  the  prawn,  he  finds  that  the  rods  towards  the  perijihery  of  the 
eyes  exhibit  a  marked  flexure.     The  paper  is  accomjianied  by  a  plate. 

Poison  Glands  of  the  Centipedes. — It  has  long  been  known  that 
the  Chilopod  Myriapoda,  commonly  known  as  centipedes,  which  are 
carnivorous  in  their  habits,  kill  their  prey  by  a  poison  injected  at  the 
first  bite  of  their  formidable  nippers.  The  seat  of  the  glands  secreting 
the  poisonous  fluid  was,  however,  unknown,  the  organs  formerly  suj)- 
posed  to  secrete  the  venom  being  found  to  j)oui-  their  secretion  into 
the  cavity  of  the  mouth  and  not  into  the  nijjpers.  Mr.  McLeod, 
during  a  residence  in  Java,  examined  some  of  the  large  centipedes 
with  which  that  island  abounds,  and  esiJecially  Scolopenclra  horrida, 
and  finding  the  glands  which  might  easily  be  taken  for  poison  glands 
had  nothing  to  do  with  the  nippers,  which  nevertheless  always  ex- 
hibited a  very  distinct  oritice  at  the  tip,  he  was  led  to  search  for  the 
glands  in  the  interior  of  those  organs  themselves. 

The  process  he  adopted  is  one  that  has  of  late  given  admirable 
results  in  the  investigation  of  the  anatomy  of  many  animals ;  namely, 
the  preparation  of  sections  of  them  in  various  directions,  after  they 
had  been  immersed  in  melted  paraffin,  the  subsequent  hardening  of 
which  keeps  all  parts  in  their  natural  positions  during  the  ojieration 
of  cutting.     By  this  means  he  detected  the  poison  gland,  which  is 


58  NOTES    AND    MEMORANDA. 

situated  partly  in  the  actual  biting  portion  of  the  nipper  and  partly 
in  the  broad  basal  joint  which  supports  the  latter.  The  glandular 
apparatus  consists  of  a  chitinous  duct  leading  to  the  orifice  at  the 
apex  of  the  organ,  and  forming  the  axis  of  the  gland.  It  is  perforated 
in  its  course  by  a  multitude  of  small  apertures,  each  of  which  leads 
into  a  minute  cylindrical  tube,  terminating  in  a  long  secreting  cell, 
the  whole  mass  of  these  cells  being  arranged  in  a  radiating  fashion 
around  the  duct.  The  entire  organ  is  surrounded  by  a  membrane,  and 
has  the  general  form  of  a  four-sided  prism.  Notwithstanding  its 
comparatively  small  size,  Mr.  McLeod  has  detected  the  same  arrange- 
ment in  Lithohius  forjicatus,  the  common  European  centipede.* 

Microbia. — Under  the  title  of  "  The  Influence  of  M.  Pasteur's 
Discoveries  on  the  Progress  of  Surgery,"  M.  Sedillot  contributes  a 
paper  to  the  French  Academy,f  which  he  commences  by  pointing  out 
that  the  microscopical  organisms  pervading  the  atmosphere  (which 
Pasteur  has  shown  are  the  caiise  of  the  fermentations  attributed  to 
the  air,  which  is  merely  their  vehicle),  form  a  world  by  themselves, 
the  history  of  which,  as  yet  in  its  infancy,  has  already  proved  fertile 
in  conjectures,  and  in  results  of  the  highest  importance. 

The  names  of  these  organisms  are,  however,  very  numerous  : — 
Miciozoaria,  Microphyta,  Aerobia,  Anaerobia,  Microgerms,  Micro- 
cocci, Mici'ozymes,  Bacteria,  Bicteridia,  Vibrions,  Microderms,  Con- 
fervfe.  Ferments,  Monads,  Animalcules, Corpuscles,  Torulae,  PenicilUum, 
Aspergillus,  Infusoria,  Leptothrix,  Leptotrichum,  S^Dores  of  Achorion, 
of  Fuvus,  of  Oidium,  of  thrush.  Organisms  of  right  and  left  tartaric 
acid,  septic  and  septicemic  Zymes,  &c.,  terms  which  need  to  be 
defined  and  partly  reformed.  The  word  Microbia  (from  mihros,  small, 
and  hios,  life)  has  the  advantage  of  being  shorter  and  of  a  more 
general  signification,  and  of  being  approved  by  M.  Littre,  the  most 
competent  linguist  in  France  ;  and  the  author  therefore  proposes  it  for 
general  acceptance,  without,  however,  laying  aside  altogether  those 
terms  in  use  to  designate  varieties  which  have  been  more  particularly 
examined.     M.  Pasteur  also  approves  of  the  term. 

The  paper  proceeds  to  discuss  the  changes  in  surgery  which  were 
brought  about  by  the  proof  of  the  existence  of  Microbia,  and  "  which 
threw  a  vivid  light  on  the  obscurity  and  false  conceptions  in  which 
surgery  had  gone  astray.  From  the  highest  antiquity  medical  science 
took  notice  of  the  preponderating  influence  of  the  air  on  health  and 
disease  ;  but,  in  spite  of  the  immeuse  progress  of  science,  time  brought 
about  no  change  in  this  point  of  view  until  the  discoveries  of  M.  Pas- 
teur essentially  modified  the  position  of  surgery  and  the  treatment  of 
wounds  in  particular.  Surgeons  were  divided  by  different  doctrines, 
reducible  to  a  single  one  having  for  its  basis  '  the  dangers  of  contact 
with  air.'  All  were  founded  on  observations  which  were  exact  and 
approached  to  truth,  without,  however,  attaining  it  by  reason  of  false 
interpretations  and  hasty  generalizations.  The  discoveries  of  M.  Pas- 
teur at  once  reconciled  the  apparent  contradictions,  and  explained  the 

*  'Bull.  Acad.  Roy.  de  Belgiqiic,'  vol.  xlv.  'Pop.  Sc.  Eev.,'  N.  S.,  vol.  iii. 
p.  111. 

t  '  Compto.s  Eeniliis,'  vol.  Ixxxvi   p.  fi.S4. 


NOTES    AND    MEMORANDA.  *  59 

use,  in  the  treatment  of  wounds,  oT  pulverulents,  styptics,  balms,  oint- 
ments, caustics,  camphor,  iodine,  alcohol,  and  a  hundred  other  anti- 
septic substances  which  act  as  barriers  to  the  contact  of  Microbia, 
or  as  agents  of  their  destruction.  Herein  lies  the  principle  of  all 
preservative  and  curative  treatment.  Medicine  and  hygiene  is  applied 
to  the  destruction  of  the  Microbia,  external  and  internal,  and  to 
augment  the  vital  resisting  power  of  the  patient. 

The  cultivation  in  fluids  of  Cohn,  Eauliu,  and  Pasteur  has  shown 
that  certain  species  of  Microbia  (Aspergillus  niger  amongst  others) 
have  never  been  found  amongst  the  jDreparations  impregnated  by  the 
passage  of  a  given  quantity  of  air.  Yet  to  procure  this  cryptogam  it 
suffices  to  expose  a  slice  of  moist  bread  to  the  air,  when  they  are 
soon  seen  to  grow.  This  fact  fully  explains  the  variety  of  accidents 
to  wliich  wounds  may  be  subject  by  reason  of  the  numberless  modify- 
ing circumstances  which  render  them  more  or  less  amenable  to  the 
development  and  increase  of  different  Microbia."  It  would  be  very 
desirable,  he  thinks,  "  to  set  up  apparatus  for  analyzing  the  air  in 
hospitals  by  which  the  degree  of  salubrity  or  infection  would  be  daily 
determined." 

Orchella  as  a  Staining  Material.  —  Dr.  C.  Wedl,  of  Vienna, 
describes  the  following  process  of  staining  animal  tissues,  in 
Virchow's  '  Archiv  fiir  Pathologische  Anatomic,'  vol.  Ixxiv.  p.  143. 
The  so-called  French  Orchclla-extract,  from  which  the  excess  of 
ammonia  has  been  extracted  by  gentle  warming  in  a  sand-bath,  is 
poured  into  a  mixture  of  20  c,  cm.  absolute  alcohol,  5  c.  cm.  con- 
centrated acetic  acid  (of  1-070  spec,  grav.),  and  40  com.  distilled 
water,  till  a  saturated  dark-red  stain  is  obtained,  which  must  then  be 
once  or  twice  filtered.  Afler  the  section  has  been  hardened  in 
Muller's  fluid  and  spirits  of  wine  or  chromic  acid,  it  is  washed  with 
distilled  water.  The  latter  is  then  got  rid  of  by  means  of  blotting- 
paper,  and  some  drops  of  the  staining  fluid  are  applied  to  the  section. 
The  stain  is  taken  up  immediately  by  the  protoplasm  of  the  cells, 
whilst  nuclei  and  nucleoli  are  not  coloured.  Horny  or  calcareous 
epithelial  formations  likewise  take  no  stain.  Connective-tissue  cells 
are  very  deeply  coloured,  whilst  the  fibrillated  intercellular  substance 
of  the  connective  tissue  takes  less  of  the  stain.  The  basic  substance 
of  bones  and  that  of  the  teeth  take  the  stain,  also  the  ganglion-cells 
with  their  prolongations.  Fresh  pathological  formations  also  give 
sharp  images  when  coloured  with  orchella.  As  medium  the  author 
used  levulose* 

Construction  of  Eye-pieces. —In  consequence  of  the  discrepancies 
in  j)ublished  statements  in  regard  to  eye-pieces,  Mr.  W.  H.  Seaman, 
of  Washington,  has  made  a  full  series  of  measurements  of  the  parts  of 
eighteen  eye-pieces  by  English  and  Continental  makers.  As  the 
result  of  these  measurements  (which  were  laid  before  the  Indianapolis 
Congress  f),  it  was  found  that  the  common  ratio  between  the  focal 
lengths  of  eye-lens  and  field-lens  was  \,  in  one  instance  it  was  ^,  and 

*  '  Zeitsclirift  fiir  Mikroskopie,'  vol.  i.  p.  318. 
t  '  Ameiican  Naturalist,'  vol.  xii.  p.  838. 


00  •  NOTES    AND   MEMORANDA. 

in  one  of  olclcr  construction  |^.  "  The  only  general  principle  in  regard 
to  tlie  interval  separating  the  lenses  is,  that  it  shall  be  less  than  the 
solar  focus  of  the  field-lens ;  and  when  in  the  deeper  eye-pieces  and 
those  which  are  orthoscoiiic  it  seems  to  exceed  this  limit,  it  must 
be  remembered  that  in  connection  with  the  objective  the  eye-piece 
receives  diverging  rays,  and  for  such  its  focus  is  beyond  the  solar 
focus.  It  may  also  be  noticed  that  but  a  small  part  of  the  diameter  of 
the  eye-' ens  is  actually  used  in  the  lower  powers." 

Malpighian  Vessels  of  Insects. — Dr.  E.  Schindler  has  published 
an  account,  with  three  jdates  and  a  woodcut,  of  his  extended  researches 
on  these  structures.*  This  paper  gives,  first,  an  general  account  of 
the  structure  of  the  vessels  in  question,  then  an  historical  summary 
of  the  work  of  former  observers,  then  a  special  account  of  the 
Malpighian  vessels  in  the  various  groups  of  insects,  and  finally  some 
concluding  remarks,  summarizing  the  results  at  which  he  has  arrived. 
It  is  only  possible  here  to  give  some  account  of  the  first  and  last  of 
these  sections. 

The  Malpighian  vessels  consist  of  at  least  three  layers  :  externally 
a  serous  coat  of  nucleated  connective  tissue,  then  a  delicate  homo- 
geneous tanica  propria,  and  finally  a  single  layer  of  glandular 
epithelial  cells  bounding  the  lumen  of  the  tube.  To  these  is  some- 
times added  a  perforated  cuticular  tunica  intima.  Elastic  and 
muscular  layers  are  but  little  developed,  and  the  flow  of  the 
secretion,  set  free  by  the  dehiscence  of  the  gland-cells,  is  produced 
partly  by  its  own  gradual  accumulation,  partly  by  the  movements  of 
the  other  organs.  The  tubes  may  appear  white,  yellow,  brown,  green, 
or  red,  according  to  the  colour  and  quantity  of  their  contents.  Their 
size  and  number  vary  greatly,  their  length  being,  as  a  rule,  inversely 
proportional  to  their  number. 

The  Malpighian  vessels  are  exclusively  excretory  (renal)  organs, 
and  not,  as  has  been  supposed,  biliary,  or  both  biliary  and  renal. 
This  is  supported  by  their  mode  of  development  as  outgrowths  of 
the  hind-gut  by  their  early  origin,  and  by  the  fact  that  they  are 
functional  before  any  bile  is  found  and  while  the  hind-gut  is  still  a 
blind  jiouch,  but  chiefly  by  their  close  resemblance  to  the  urinary 
tubules  of  higher  animals,  and  by  the  nature  of  their  contents.  It  is 
well  made  out  that  they  contain  specific  urine-constituents,  such  as 
uric  acid,  acid  sodic  and  amnionic  urates,  leucin,  calcic  oxalate,  &c., 
and  that  no  substance  not  already  known  in  the  urine  of  other 
animals  occurs  in  them. 

The  chief  facts  tending  to  support  the  theory  that  these  tubes  are 
hepatic  as  well  as  renal,  are  the  yellow  and  green  colours  often 
observed  in  them,  and  the  polymorphism  of  their  epithelial  cells. 
With  regard  to  the  first  of  these  points,  Schindler  states  that  the 
colour  is  dependent  on  a  specific  colouring  matter  in  the  blood 
plasma,  that  no  bile  pigments  are  present,  and  that  the  colour  is  very 
inconstant.  The  polymorphism  of  the  cells  was  used  as  an  argument 
for  double  function  by  Ley  dig,  who  supposed  that  certain  cells  had 
assigned  to  them  a  hepatic,  others  a  renal  function.  But  according 
*  '  ZeitSL'h.  f.  wiss.  Zool.,'  vol.  xxx.  p.  587. 


NOTES    AND    MEMOKANDA,  61 

to  Schindler  there  is  no  constancy  in  the  occurrence  of  the  diflferent 
forms  of  cells,  and  moreover  all  of  them  contain  the  characteristic 
ui'inary  concretions. 

The  urinary  epithelium  of  insects  contains  none  of  the  so-called 
Dauer-zellen  or  long-lived  cells,  but  renewal  of  the  cells  takes  place 
either  by  division,  or  (probably)  by  the  nucleus  of  a  cell  which  has 
undergone  dehiscence,  enlarging  to  form  a  new  cell,  its  nucleolus 
becoming  the  nucleus  of  the  latter. 

Parasitic  Crustacea. — M.  Hesse  gives  the  name  of  Pachjnesthus 
violaceus  and  Polyoon  luteum  to  two  new  parasitic  crustaceans  of 
microscopic  dimensions  (1-2  mm.),  two  females  of  which  were  dis- 
covered in  the  harbour  at  Brest,  enclosed  in  the  interior  of  a  comjiound 
ascidian.  The  genera  are  new.  M.  Hesse  remarks  *  in  regard  to  their 
life-history: — 

The  completely  stationary  and  so  to  speak  secluded  existence,  to 
which  these  Crustacea  are  condemned,  does  not  requrre,  as  in  the  case 
of  those  which  live  in  a  free  condition,  perfect  means  of  locomotion 
for  which  they  would  have  no  use ;  those  which  they  do  possess  are 
rather  destined  to  serve  for  creeping  than  swimming. 

Constantly  shut  up  in  an  extremely  limited  enclosure  formed  of  a 
more  or  less  hard  test  of  cellulose,  they  are  obliged,  in  order  to  move 
in  these  narrow  dwellings,  to  make  themselves  a  passage  by  main  force 
and  as  Professor  Giard  has  very  well  observed  in  his  remarkable  work 
on  Synascidia,  they  are  obliged  to  make  galleries,  by  means  of  which 
they  introduce  themselves  into  the  viscera;  they  penetrate  into  the 
ovaries,  and  produce  such  disorders  as  often  cause  the  death  of  the 
whole  colony,  and  might  lead  to  the  belief  in  the  existence  of  a  new 
species,  although  these  modifications  are  only  the  result  of  the  dis- 
turbances which  they  have  produced  in  the  individuals. 

This  work  of  burrowing,  which  I  will  compare  to  that  of  the  mole 
cricket,  results  in  the  disappearance  of  the  common  cloacfe  and  their 
replacement  by  small  openings  very  near  together,  the  utility  of  which 
to  these  Crustacea  is  easily  conceived.  Without  these  issues,  in  fact, 
the  young  embryos  could  not  quit  the  enclosure  nor  disseminate  them- 
selves, and  thus  contribute  to  the  dispersion  of  their  species,  and  the 
males  would  be  imprisoned  and  reduced  to  a  state  of  captivity  which 
is  evidently  contrary  to  the  role  which  they  have  to  fulfil,  if  I  judf^e 
from  Crustacea  closely  allied  to  these,  with  which  I  am  acquainted, 
and  which  are  extremely  agile  and  provided  with  all  necessary  means 
of  swimming  with  facility. 

Moreover,  this  liberty  which  the  males  enjoy  easily  explains  their 
rarity,  or  rather  the  difficulty  which  there  is  in  procuring  them. 
They  are  rarely  sedentary.  It  is  of  course  on  this  account  that  they 
are  more  seldom  met  with  than  the  females,  which  are  condemned 
to  live  always  in  confinement.  These  latter  are  besides  rather  difficult 
to  see,  by  reason  of  their  extreme  smallness ;  and  if  it  were  not  for  the 
eggs,  which  are  generally  of  a  very  marked  colour  and  which  denote 
their  presence,  they  would  often  not  be  seen. 

The  means  of  locomotion  with  which  these  Crustacea  arc  endowed 
*  '  Auu.  des  Sci.  Nat.  Zool.,'  Cth  ser.,  vol.  vii.  p.  7. 


62  NOTES    AND    MEMORANDA, 

in  order  to  surmouut  the  obstacles  which  oppose  their  passage  into 
the  midst  of  the  viscera  of  the  Synascidians,  consist  of  thoracic  limbs, 
which  are  rather  long  and  slender,  and  are  terminated  either  by  a 
single  hooked  claw,  as  in  the  Pohjoon,  or  by  several,  as  in  the  Pachy- 
nesthus.  There  may  be  further  observed,  in  both,  the  cupulfe  placed 
at  the  base  of  the  legs  from  which  they  emerge,  which,  by  their  con- 
tractions and  the  ease  with  which  they  assume  several  shapes,  can  be 
applied  like  suckers  to  surfaces  and  be  fixed  there,  or  being  lengthened 
into  a  point,  they  may  serve  as  means  of  propulsion. 

Finally,  it  is  not  uninteresting  to  observe  the  mode  of  termination 
of  the  abdominal  extremity  in  these  two  Crustacea. 

In  the  one  {Pacliynesthus)  it  presents  an  appendage  armed  with 
two  divergent  points,  in  the  form  of  a  dovetail ;  underneath  these  are 
two  other  points  directed  perpendicularly,  a  combination  which  seems 
to  me  designed  to  draw  up  or  drive  away  objects,  as  is  done  by  the 
hoat-hooJc  emj^loyed  by  sailors  for  the  same  purpose. 

Polyoon  likewise  has  the  extremity  of  the  abdomen  armed  with  two 
claws,  which  instead  of  being  flat,  are  rounded,  short,  hooked,  and  ter- 
minated by  a  sharp  point.  They  can  also  be  raised,  and  then  serve 
for  propulsion,  or  be  lowered,  and  on  being  drawn  together,  seize 
objects  so  as  to  draw  them  up  and  furnish  a  point  of  support  for  a 
retrograde  movement.* 

As  to  the  alimentation  of  these  animals,  I  am  necessarily  reduced 
to  conjecture ;  but  it  does  not  seem  to  mo  possible  that  they  should 
live  otherwise  than  at  the  expense  of  their  hosts,  either  on  their 
material,  their  secretions,  or  their  eggs. 

The  form  of  the  mouth,  which  generally  gives  such  valuable  indi- 
cations concerning  iis  use,  does  not  here  lead  to  any  definite  conclusion, 
seeing  that  it  can  serve  as  well  for  suction  as  for  mastication  ;  we  may 
therefore  presume  that  it  is  employed  for  both  purposes.  It  seems 
evident  that  it  should  be  so,  for  without  that  the  Crustacea,  who 
cannot  seek  their  food  outside,  would  infallibly  perish  if  they  did  not 
find  within  their  reach  all  that  was  necessary  for  them.  (The  species 
are  figured.) 

Improvements  in  Micro  -  photography. — Since  the  year  1844, 
when  the  first  micro-iihotographic  productions  of  Donne  and  Foucault 
appeared  in  the  form  of  an  atlas  of  microscopic  anatomy,  in  which  the 
plates  were  taken  from  daguerrotypes,  histologists  and  microscopists 
have  been  unable  to  reconcile  themselves  to  introducing  photography 
generally  as  an  integral  part  of  microscopic  research,  in  spite  of  the 
excellent  publications  of  Gerlach  and  Benecke.  Only  in  particular  cases, 
when  the  inquirer  was  familiar  with  the  application  of  photography 
to  other  purposes,  lias  it  been  applied  to  produce  pictorial  representa- 
tions of  microscopic  preparations.  And  yet  the  advantages  which  arise 
from  such  a  method  of  delineating  objects  are  beyond  criticism  and 
universally  admitted. 

The  reason  for  this  has  been  the  complicated  methods  of  preparing 
the  sensitive  plates.     There    was  also  required  not    only   a   micro- 

*  It  is  particularly  remarkable  that  the  greater  number  of  parasitic  Crustacea 
which  live  in  the  interior  of  the  ascidians,  present  similar  dispositions. 


NOTES    AND   MEMORANDA.  63 

photographic  camera,  which  in  one  way  or  another  had  to  be  connected 
with  the  tube  of  the  microscope,  but  also  a  small  photographic  atelier 
with  a  dark  chamber.  It  required  a  certain  time  to  learn  how  to 
prepare  the  plates,  and  many  thought  that  they  could  only  acquire 
skill  in  working  from  a  course  taken  under  a  practical  photographer. 

The  important  advances  in  general  photography  have  now  been 
extended  to  the  application  of  it  to  microscopical  research,  and 
endeavours  have  been  made  for  some  time  to  discover  a  process  which 
will  obviate  the  inconvenience  of  a  photographic  dark  chamber  and 
of  having  to  prepare  the  plates  each  time,  and  which  will  allow  of  the 
sensitive  plates  being  kept  in  stock,  so  that  their  complete  sensitive- 
ness is  preserved  for  an  indefinite  time. 

Of  late  years,  the  most  various  methods  of  preparing  photographic 
dry  plates  have  been  proposed.  The  best,  most  tested,  and  surest 
process,  however,  is  that  of  F.  Wilde,  of  Gorlitz,  who  has  recently 
tested  most  carefully  various  approved  forms  of  the  dry  process,  and 
so  improved  it  that  anyone  by  keeping  closely  to  the  directions  given 
with  the  plates,  which  can  be  obtained  ready  prepared,  is  in  a  position 
to  produce  excellent  photographic  pictures.  A  dozen  prei^ared  plates, 
each  containing  from  70  to  80  square  centimetres  of  surface,  cost 
tix  to  seven  shillings. 

I  *  have  occupied  myself  now  for  nearly  twenty  years  in  my  leisure 
moments  with  the  apj)lication  of  photography  to  subjects  of  natural 
history,  either  generally,  or  specially  in  microscopic  work,  and 
possess  the  requisite  facility  in  all  photographic  manipulations.  In 
spite  of  this,  however,  since  I  have  become  acquainted  with  Wilde's 
dry  plates  I  have  laid  aside  every  other  contrivance,  and  work  only 
with  that  process.  No  method  others  the  same  certainty,  entails  so 
little  loss  of  time,  and  allows  of  such  simple  working,  and  I  can  there- 
fore recommend  it  in  the  most  pressing  manner  to  my  collaborators. 

For  the  benefit  of  those  who  might  wish  to  prepare  the  jilates 
themselves,  it  may  be  stated  that  the  sensitive  covering  consists  of  an 
emulsion  of  collodion,  in  which  various  salts  of  silver,  chiefly 
bromide  of  silver,  are  suspended.  Glass  plates  upon  which  a  solution 
of  1  gramme  of  caoutchouc  in  150  to  200  grammes  of  benzine  has 
been  poured,  are  covered  with  this  emulsion,  which,  every  time  it  is 
used,  must  be  well  shaken,  and  then  allowed  to  rest  again  for  some 
minutes.  When  the  film  has  set  a  little  the  plates  must  be  forthwith 
dried  by  the  application  of  moderate  heat,  which  may  be  done  either 
in  a  small  drying  oven,  or  by  moving  them  to  and  fro  over  a  plate 
beneath  which  a  spirit  lamp  is  placed;  after  being  dried,  the  plate 
is  ready  for  use,  either  at  once  or  at  any  subsequent  time. 

To  use  the  plates  all  that  is  necessary  is  a  conical  tube  for  the  end 
of  the  microscope,  such  as  I  have  fully  described  in  my  work  on 
'  Light  as  Employed  in  Scientific  Research,'  page  Slo,  the  wide  end 
of  which  is  placed  uppermost.  Connected  with  the  tube  is  a  cross 
piece  on  which  the  photograjihic  cassette  and  the  ground  glass  are 
placed.  Such  an  apparatus,  which  can  be  got  complete  for  about 
20s.,  is  quite  sufficient  to  obtain  the  most  beautiful  micro-photographs 
*  Dr.  S.  Th.  Stein,  in  '  Zeitschrift  fiir  Mikioskopie,'  vol.  i.  p.  140. 


64  NOTES   AND   MEMORANDA. 

by  means  of  dry  plates.  If  a  considerable  number  of  small  cassettes 
are  prepared,  you  can  provide  them  with  the  dry  plates  in  the  evening, 
and  the  next  day,  as  wanted,  take  inicro-photographs.  These,  for 
which  according  to  the  intensity  of  the  light  one  second  up  to  several 
minutes  are  required,  may  be  let  stand  till  the  evening  if  you  are  not 
in  a  position  to  darken  your  room,  in  order  that  you  may  at  one  and 
the  same  time  develop  and  fix  the  pictures.  The  time  required 
dejiends  of  course  on  the  source  of  light.  If  direct  sunlight  is 
used  with  a  low  magnifying  power,  a  perfect  photograjjh  may 
be  produced  in  a  fraction  even  of  a  second.  With  a  magnifying 
power  of  200  to  500  diameters,  the  time  of  exj^osure  required  with  sun- 
light is  from  twenty-five  seconds  to  half  a  minute,  under  some  circum- 
stances a  whole  minute.  Bright  daylight  or  sunlight  reflected  from  a 
bright  cloud  requires  even  with  low  powers  fi'om  a  half  to  two  and 
even  three  minutes.  High  powers  cannot  be  used  in  diffused  daylight. 
Magnesium  light  offers  a  good  substitute,  and  by  employing  it  with 
Wilde's  dry  plates  superior  "  photograms  "  are  obtained  even  with  very 
high  amj)lification.  The  time  of  exposure  is  in  proportion  to  the 
intensity  of  the  light.  Magnesium  light  is  about  forty  times  weaker 
than  sunlight,  consequently  the  time  of  exposure  required  for  a 
photograph  with  magnesium  light  is  about  forty  times  as  long  as 
with  direct  sunlight :  for  low  powers  therefore  a  period  of  about 
three-quarters  of  a  minute,  for  high  jjowers  a  2)eriod  of  from  several 
minutes  to  a  quarter  of  an  hour.  The  latter  period  is  requisite  with 
the  highest  i:)owers  which  as  yet  it  has  been  possible  to  employ  for 
photograj)hic  purposes. 

The  further  development  and  fixing  of  the  image  is  effected 
according  to  Wilde's  directions  in  the  following  manner  : — 

First,  over  the  plate  which  has  received  the  impression  there  is 
poured,  to  develop  it,  a  solution  of 

20  cubic  centimetres  alcohol, 
5      „  „  distilled  water, 

10  droijs  of  the  solution  B  (below)  of  bromide  of  potash, 

and  it  is  left  to  the  action  of  this  mixture  one  to  two  minutes;  then  it 
is  carefully  rinsed  with  water  till  all  greasy  streaks  have  disappeared, 
and  the  water  flows  quite  evenly  over  the  plate. 

In  the  development  the  following  solutions  are  wanted : — 

A.  5  grammes  pyrogallic  acid,  25  cubic  centimetres  alcohol,  25  cubic  centi- 
metres distilled  water. 

B.  5  grammes  bromide  of  potash,  75  cub.  ceutim.  distilled  water. 

C.  3  grammes  gelatine,  20  cub.  ceutim.  of  acetic  acid,  400  cub.  centim.  dis- 
tilled water. 

D.  25  grammes  of  carbonate  of  ammonia,  150  cub.  centim.  of  distilled  water. 

Shortly  before  it  is  wanted  for  use  a  mixture  is  made  of 

40  drops  of  A. 

20        „        B. 

10-15        „        C. 

15  cub.  cm.  D. 

The  latent  image  is  washed  over  with  this  mixture  and  kciA  moist 
for  several  minutes  by  repeated  washings. 


NOTES    AND    MEMORANDA. 


65 


After  the  image,  complete  in  all  its  details,  has  by  this  means 
been  developed,  it  is  washed  by  pouring  water  over  it,  and  fixed  by 
dipping  it  in  a  solution  of  hyposulphite  of  soda  (1  to  10).  It  is 
again  washed,  dried,  and  varnished. 

The  process  of  taking  prints  is  conducted  in  the  same  way  as  in 
ordinary  photography  ;  a  very  practical  and  simple  method  is  that  by 
means  of  sulphate  of  iron.  A  durable  prepared  paper  may  be 
obtained  from  Marion  and  Gevy,  of  Paris,  which  gives  excellent  copies 
in  blue  colour,  without  any  special  skill  being  required. 

Measure  for  Covering  Glass. — For  the  exact  measurement  of  the 
thickness  of  covering  glass  to  hundredths  of  a  millimetre  two  dif- 
ferent mechanical  appliances  have  hitherto  been  employed — the  screw 
and  the  lever.  The  editor  of  the  '  Zeitschrift  fiir  Mikroskopie '  * 
points  out  that  the  same  object  may  be  attained  by  a  suitable  adapta- 
tion of  a  movable  wedge,  the  measuring  wedge  invented  by  P.  Schone- 
mann,  which  is  distinguished  by  its  great  simplicity  and  solidity,  and 
has  recently  been  considerably  improved. 

The  geometrical  principle  of  the  ajDparatus  is  as  follows : — If  a 
right-angled  triangle  ab  c  (Fig.  1),  whose  hypothenuse  ac  =  5  cm.. 

Fig.  1. 


and  its  perpendicular  ah  =  1  cm.,  moves  between  the  fixed  lines  m  n 
and  op  in  such  a  way  that  ac  slides  along  wn;  then  the  line  ch 
(1)  always  remains  parallel  to  op,  (2)  the  distance  between  the  movable 
line  cb  and  the  fixed  line  op  will  always  be  one-fifth  part  of  the  dis- 
tance which  the  point  c,  or  any  other  point  of  the  hypothenuse  a  c,  has 
moved  from  its  original  position. 

If,  for  instance,  the  triangle  ab  c  moves  to  a  a'  b',  the  point  c  will 
have  moved  over  the  distance  a  c  =  5  cm.,  while  the  line  c  b  will  have 
moved  to  the  distance  a  6  =  1  cm.  from  the  fixed  line  op. 

It  is  on  this  principle  that  the  construction  of  Schonemann's  gauge 
is  based,  as  shown  in  Figs.  2  and  3. 


Fig. 

2. 

I..l,  I..I. 

^,?,  f,^ 

O 

^^^^ 

dT"^ 

■*  _ 

) 

\o 

"^         . 

Fig. 

3. 

l".  ' 

, 1  ,^  .T  f  . 

o 

o\ 

ll= 

•^^ 

■^ 

) 

Vo 

o\      ; 

On  one  of  the  long  sides  of  a  brass  base-plate  a  scale  is  fixed, 
the  divisions  on  which  are  half  a  millimetre  apart.  On  the  other 
long  side  is  a  piece  of  brass  bent  inwards  {d.  Fig.  2).  Between 
these  a  wedge,  provided  with  a  nonius,  can  be  moved  backwards  and 


Vol.  i.  p.  283. 


VOL.    II. 


6()  NOTES    AND   MEMORANDA. 

foi'wai'ils  by  means  of  two  buttons,  and  is  prevented  from  falling  ont 
by  proper  guides  in  the  slit  of  the  base-plate. 

When  the  long  side  of  the  wedge  is  contiguoiTS  to  the  edge  of  the 
beaked  piece  d  (Fig.  2),  the  first  line  on  the  nonius  coincides  with  the 
zero  point  of  the  scale. 

To  measure  the  thickness  of  a  covering  glass,  the  wedge  is  drawn 
back  till  the  object  to  be  measured  can  be  placed  on  the  edge  of  the 
piece  d  (Fig.  3).  Then  it  is  moved  back  again,  pressing  it  slightly 
against  the  scale  until  a  check  is  felt  to  the  motion.  The  first  line  on 
the  nonius  will  now  no  longer  coincide  with  the  zero  point  on  the 
scale  (Fig.  3).  The  number  of  divisions  denoted  by  figures  gives  the 
whole  millimetres,  the  number  of  smaller  divisions  the  tenths  of  a 
millimetre,  and  the  nonius  the  hundredths  of  a  millimetre. 

In  using  the  instrument,  care  should  be  taken  that  it  is  free  from 
dust,  and  that  the  motion  of  the  wedge  is  easy. 

By  this  instrument,  when  neatly  and  correctly  made,  the  most 
exact  measurements  can  be  taken  with  a  rapidity  and  ease  that  even  a 
well-made  screw  micrometer  will  not  admit  of. 

Origin  of  the  Sexual  Products  in  Hydroids. — J.  Ciamician  has 
made  a  series  of  careful  observations  *  on  the  exact  mode  of  origin  of 
the  ova  and  spermatozoa  in  two  genera  of  Hydroida,  and  his  results 
are  altogether  opposed  to  the  theory  of  Van  Beneden,  according  to 
which  the  ectoderm  may  be  looked  upon  as  the  male,  the  endoderm 
as  the  female  germ-lamella.  In  Tuhularia  mesemhryanlhemum  the 
reproductive  organs  are  sporosacs,  and  arise  as  bud-like  processes 
composed  of  ectoderm  and  endoderm.  The  ectoderm  at  the  distal 
end  of  this  bud  undergoes  a  process  of  invagination,  and  the  bottom 
of  the  sac  thus  produced  growing  distalwards,  forms  from  its 
endoderm  the  spadia  of  the  sporosac,  from  its  ectoderm  the  ova  or 
sperm-mother-cells.  The  generative  products  of  both  sexes  are 
therefore  products  of  the  ectoderm. 

In  Eudendrium  ramosinn  the  ectoderm  on  one  side  of  the  female  gene- 
rative bud  undergoes  proliferation,  and  pushes  the  endoderm  towards 
the  opjiosite  wall :  one  of  the  ectodermal  cells  thus  pushed  in,  enlarges 
greatly  and  produces  an  ovum,  which  is  finally  enclosed,  by  the  com- 
pletion of  the  process  of  virtual  invagination,  by  a  double  layer  of 
endoderm  and  a  single  one  of  ectoderm.  So  that  in  this  case  also, 
the  ova  are  ectodermal  products. 

In  the  male  gonophore  of  the  same  species,  the  case  is  quite 
different.  Certain  of  the  cells  of  the  endoderm — the  sperm-mother- 
cells — enlarge  greatly,  and  their  nuclei  undergo  extensive  multiplica- 
tion :  as  growth  proceeds  they  become  completely  overarched  by  the 
neighbouring  endoderm  cells,  and  finally  come  to  lie  between  the  two 
layers,  often  having  the  appearance  of  belonging  rather  to  ectoderm 
than  to  endoderm.  Their  contents  become  converted  into  sperma- 
tozoa, which  are  thus  endodermal  products. 

There  is,  therefore,  almost  every  possible  variation  in  the  origin 
of  the  generative  products  among  the  Hydrozoa ;  in  Tuhularia 
(Ciamician)  and  in  Hydra  (Kleinenberg),  both  male  and  female 
*  '  Zcitsch.  f.  wiss.  Zoo].,'  vol.  xxx.  p.  501. 


NOTES   AND    MEMOKANDA.  67 

elements  are  ectodermal ;  in  Hydractinia  (Van  Beneden)  the  ova  are 
eadodermal  and  the  spermatozoa  f  ctodermal ;  lastly,  in  Eudendrhim 
(Ciamician)  the  ova  are  ectodermal  and  the  spermatozoa  endodermal. 
Ciamician  supposes  that  the  generative  products  arose  in  the  first 
instance  indifferently  from  either  layer,  and  that  by  further  develop- 
ment they  left  their  original  position  and  came  to  lie  between  the  two 
lamellae. 

Sir  Joseph  Hooker  on  the  Modern  Development  of  Micro- 
botany. —  Sir  Joseph  Hooker  devoted  part  of  his  address  as  President 
at  the  last  anniversary  meeting  of  the  Royal  Society  to  the  modern 
development  of  botanical  science,  there  being,  as  he  pointed  out, 
perhaps  no  branch  of  research  with  the  early  progress  of  which  the 
Society  was  more  intimately  connected. 

"  One  of  our  earliest  secretaries,  Robert  Hooke,  two  centuries  agOj 
laboured  long  and  successfully  in  the  improvement  of  the  microscope 
as  an  implement  of  investigation.  He  was  one  of  the  first  to  reap 
the  harvest  of  discovery  in  the  new  fields  of  knowledge  to  which  it 
was  the  key,  and  if  the  results  which  he  attained  have  rather  the 
aimless  air  of  spoils  gathered  hither  and  thither  in  a  treasury,  the 
very  fulness  of  which  was  embarrassing,  we  must  remember  that  we 
date  the  starting-point  of  modern  histology  from  the  account  given 
by  Hooke  in  his  '  Micrographia '  (1667)  of  the  structure  of  cork, 
which  had  attracted  his  interest  from  the  singularity  of  its  physical 
properties.  Hooke  demonstrated  its  cellular  structure,  and  by  an 
interesting  coincidence  he  was  one  of  the  first  to  investigate,  at  the 
request,  indeed,  of  the  founder  of  the  Society,  Charles  II.,  the 
movement  of  the  sensitive  plant  Mimosa  imdica,  one  of  a  class  of 
phenomena  which  is  still  occupying  the  attention  of  more  than  one  of 
our  Fellows.  In  attributing  the  loss  of  turgescence,  which  is  the 
cause  of  the  collapse  of  the  petiole  and  subordinate  portions  of  the 
compound  leaf  which  it  supports,  to  the  escape  of  a  subtle  humour, 
he  to  some  extent  fi  -reshadowed  the  modern  view  which  attributes  the 
collapse  of  the  cells  to  the  escape  of  water  by  some  mechanism  far 
from  clearly  understood — whether  from  the  cell-cavities  or  from  the 
cell-walls  into  the  intercellular  spaces. 

Hooke  having  show^n  the  way,  Nehemiah  Grew,  who  was  also 
secretary  of  the  Eoyal  Society,  and  Marcello  Malpighi,  Professor  of 
Medicine  in  the  University  of  Bologna,  were  not  slow  to  follow  it. 
Almost  simultaneously  (1671-3)  the  researches  of  these  two  inde- 
fatigable students  were  presented  to  the  Eoyal  Society,  and  the 
publication  of  two  editions  of  Malpighi's  works  in  London  prove  how 
ertirely  this  country  was  at  that  time  regarded  as  the  head-quarters 
of  this  branch  of  scientific  inquiry.  We  owe  to  them  the  generaliza- 
tion of  the  cellular  structure,  which  Hooke  had  ascertained  in  cork, 
for  all  other  vegetable  tissues.  They  described  also  accurately  a 
host  of  microscoiiic  structures  then  made  known  for  the  first  time. 
Thus,  to  give  one  example.  Grew  figured  and  described  in  several 
different  plants  the  stomata  of  the  epidermis  : — '  Passports  either  for 
the  better  avolation  of  superfluous  saji,  or  the  admission  of  air.' 

With  the  exception  of  Leeuwenhock,  no  observer  attempted  to 

F  2 


68  NOTES   AND    MEMORANDA. 

make  any  substantial  addition  to  the  labours  of  Grew  and  Malpighi 
for  more  tban  a  century  and  a  half,  and  however  remarkable  is  the 
impulse  which  he  gave  to  morphological  studies,  the  views  of  Caspar 
Woltf  in  the  middle  of  the  eighteenth  century  (1759),  in  regarding 
cells  as  the  result  of  the  action  of  an  organizing  power  upon  a  matrix, 
and  not  as  themselves  influencing  organization,  were  adverse  to  the 
progress  of  histology.  It  is  from  Schleiden  (1838),  who  described 
the  cell  as  the  true  unit  of  vegetable  structure,  and  Schwann,  who 
extended  this  view  to  all  organisms  whether  plants  or  animals,  and 
gave  its  modern  basis  to  biology  by  reasserting  the  unity  of  organiza- 
tion throughout  animated  nature,  that  we  must  date  the  modern 
achievements  of  histological  science.  Seldom,  perhaps,  in  the  history 
of  science  has  any  one  man  been  allowed  to  see  so  magnificent  a 
development  of  his  ideas  in  the  space  of  his  own  lifetime  as  has 
slowly  grown  up  before  the  eyes  of  the  venerable  Schwann,  and  it 
was  therefore  with  jjeculiar  pleasure  that  a  letter  of  congratulation 
was  entrusted  by  the  officers  to  one  of  the  Fellows  of  this  Society  on 
its  behalf  on  the  recent  occasion  of  the  celebration  of  the  fortieth 
anniversary  of  Schwann's  entry  into  the  professoriate. 

If  we  can  call  up  in  our  mind's  eye  some  vegetable  organism  and 
briefly  reflect  on  its  construction,  we  see  that  we  may  fix  on  three 
great  steps  in  the  analysis  of  its  structure,  the  organic,  the  micro- 
scopic, and  the  molecular,  and,  although  not  in  the  same  order,  each 
of  the  three  last  centuries  is  identified  with  one  of  these.  In  the 
seventeenth  century  Grew  achieved  the  microscopic  analysis  of  plant 
tissues  into  their  constituent  cells ;  in  the  eighteenth,  Caspar  Wolff 
effected  the  organic  analysis  (independently  but  long  subsequently  ex 
pounded  by  the  poet  Goethe)  of  plant  structures  into  stem  and  leaf. 
It  remained  for  Nageli  in  the  present  century  to  first  lift  the  veil  from 
the  mysterious  processes  of  plant  growth,  and  by  his  memorable 
theory  of  the  molecular  constitution  of  the  starch-grain  and  cell-wall, 
and  their  growth  by  intus-susception  (1858),  to  bring  a  large  class  of 
vital  phenomena  within  the  limits  of  physical  interpretation.  Stras- 
burger  has  lately  (1876)  followed  Sachs  in  extending  Nageli's  views 
to  the  constitution  of  protojolasm  itself,  and  there  is  now  reason  to 
believe  that  the  ultimate  structure  of  plants  consists  universally  of 
solid  molecules  (not  however,  identical  with  chemical  molecules)  sur- 
rounded with  areas  of  water  which  may  be  extended  or  diminished. 
While  the  molecules  of  all  the  inert  parts  of  plants  (starch-grains, 
cell-wall,  &c.)  are  on  optical  grounds  believed  to  have  a  definite 
crystalline  character,  no  such  conclusion  can  be  arrived  at  with 
respect  to  the  molecules  of  protoplasm.  In  tliese  molecules  the 
characteristic  properties  of  the  protoplasm  reside,  and  are  more 
marked  in  the  aggregate  mass  in  proportion  to  its  denseness,  and  this 
is  due  to  the  close  approximation  of  the  molecules  and  the  tenuity  of 
their  watery  envelopes.  The  more  voluminous  the  envelopes,  the 
more  the  properties  of  protoplasm  merge  in  those  of  all  other  fluids. 

It  is,  however,  to  the  study  of  the  nuclei  of  cells  that  attention 
has  been  recently  paid  with  the  most  interesting  results.  These 
well-known   structures,  first   observed    by    Ferdinand    Bauer  at  the 


KOTES   AND   MEMOKANDA.  69 

beginning  of  the  century  (1802),  were  only  accurately  described, 
thirty  years  later,  by  Robert  Brown  (1833).  Up  to  the  present  time 
their  function  has  been  extremely  obscure.  The  beautiful  investiga- 
tions of  Strasburger  (1875)  have  led  him  to  the  conclusion  that  the 
nucleus  is  the  seat  of  a  central  force  which  has  a  kind  of  polarizing 
influence  upon  the  protoplasm  molecules,  causing  them  to  arrange 
themselves  in  lines  radiating  outwards.  Cell-division  he  regards  as 
primarily  caused  by  the  nucleus  becoming  bipolar,  and  the  so-called 
caryolitic  figures  first  described  by  Auerbach  exhibit  the  same 
arrangement  of  the  protoplasm  molecules  in  connecting  curves  as  in 
the  case  of  iron-filings  about  the  two  poles  of  a  bar-magnet.  The 
two  new  centres  mutually  retire,  and  each  influencing  its  own  tract  of 
protoplasm,  the  cell-division  is  thereby  ultimately  effected.  This  is 
but  a  brief  account  of  processes  which  are  greatly  complicated  in 
actual  detail,  and  of  which  it  must  be  remarked  that,  while  the 
interest  and  beauty  of  the  researches  are  beyond  question,  caution 
must  be  exercised  in  receiving  the  mechanical  speculations  by  which 
Strasburger  attemj)ts  to  explain  them.  He  has  himself  shown  that 
cell-division  presents  the  same  phenomena  in  the  animal  kingdom,  a 
result  which  has  been  confirmed  by  numerous  observers,  amongst 
whom  I  may  content  myself  with  mentioning  one  of  our  own  number, 
Mr.  F.  Balfour.  Strasburger  further  points  out  that  this  affords  an 
argimient  for  the  commimity  of  descent  in  animal  and  vegetable  cells  ; 
he  regards  free  cell-division  as  derivable  from  ordinary  cell-division 
by  the  suppression  of  certain  stages." 

The  address  then  deals  with  the  discoveries  made  during  the  last 
five  years  in  physiological  botany,  more  particularly  by  Mr.  Darwin 
and  Dr.  Burden  Sanderson. 

Lichens,  Bacteria,  Bacillus  Organisms,  and  the  Lowest  Forms  of 
Life. — Referring  to  these  subjects.  Sir  Joseph  Hooker  said,  "  In 
morphological  botany  attention  has  been  especially  directed  of  late 
to  the  complete  life-history  of  the  lower  order  of  cryptogams,  since 
this  is  seen  to  be  more  and  more  an  indispensable  preliminary  to  any 
attempt  at  their  correct  classification. 

The  remarkable  theory  of  Schwendener,  now  ten  years  old, 
astonished  botanists  by  boldly  sweeping  away  the  claims  to  auto- 
nomous recognition  of  a  whole  group  of  highly  characteristic 
organisms— the  lichens — and  by  affirming  that  these  consist  of 
ascomycetal  fungi  united  in  a  commensal  existence  with  algfe.  The 
controversial  literature  and  renewed  investigations  which  this  theory 
has  given  rise  to  is  now  very  considerable.  But  the  advocates  of  the 
Schwendenerian  view  have  gradually  won  their  ground,  and  the 
success  which  has  attended  the  experiments  of  Stahl  in  taking  up  the 
challenge  of  Schwendener's  opponents,  and  manufacturing  such 
lichens  as  Endocarpon  and  Thelidium,  by  the  juxtaposition  of  the 
appropriate  algae  and  fungi,  may  almost  be  regarded  as  deciding  the 
question.  Sachs,  in  the  last  edition  of  his  '  Lehrbuch,'  has  carried 
out  completely  the  principle  of  classification  of  algae,  first  suggested 
by  Cohn,  and  has  proposed  one  for  the  remaining  thallophytes,  which 
disregards  their  division  into  fungi  and  algae.     He  looks  upon  the 


70  NOTES   AND    MEMORANDA. 

former  as  standing  in  the  same  relation  to  the  latter  as  the  so-called 
saprophytes  (e.  g.  Neottia)  do  to  ordinary  green  flowering  plants. 

This  view  has  especial  interest  with  regard  to  the  minute 
organisms  known  as  Bacteria,  a  knowledge  of  the  life-history  of 
which  is  of  the  greatest  importance,  having  regard  to  the  changes 
which  they  effect  in  all  lifeless  and,  probably,  in  all  living  matter 
prone  to  decomposition.  This  affords  a  morphological  argument  (as 
far  as  it  goes)  against  the  doctrine  of  spontaneous  generation,  since  it 
seems  extremely  probable  that  just  as  yeast  may  be  a  degraded  form 
of  some  higher  fungus,  Bacteria  may  be  degraded  allies  of  the 
Oscillatorice,  which  have  adopted  a  purely  saprophytal  mode  of 
existence. 

Your  '  Proceedings '  for  the  present  year  contain  several  important 
contributions  to  our  knowledge  of  the  lowest  forms  of  life.  The 
Rev.  W.  H.  Dallinger,  continuing  those  researches  which  his  skill  in 
using  the  highest  microscopic  powers  and  his  ingenuity  in  devising 
experimental  methods  have  rendered  so  fruitful,  has  adduced  evidence 
which  seems  to  leave  no  doubt  that  the  spores  or  germs  of  the  monad 
which  he  has  described  differ  in  a  remarkable  manner  from  the  young 
or  adult  monads  in  their  power  of  resisting  heated  fluids.  The  young 
and  adult  monads,  in  fact,  were  always  killed  by  five  minutes' 
exposure  to  a  temperature  of  142°  F.  (61°  C),  while  the  spores 
germinated  after  being  subjected  to  a  temperature  of  10°  above  the 
boiling-point  of  water  (222°  F.). 

Two  years  ago,  Cohn  and  Koch  observed  the  development  of 
spores  within  the  rods  of  Bacillus  siibtilis  and  B.  anthracis.  These 
observations  have  been  confirmed,  with  imj)ortaut  additions,  in  these 
two  species  by  Mr.  Ewart,  and  have  been  extended  to  the  Bacillus  of 
the  infectious  pneumo-enteritis  of  the  pig,  by  Dr.  Klein  ;  and  to 
S'[)irillu7n  by  Messrs.  Geddes  and  Ewart ;  and  thus  a  very  important 
step  has  been  made  towards  the  completion  of  our  knowledge  of  the 
life-history  of  the  minute  but  important  organisms.  Dr.  Klein  has 
shown  that  the  infectious  pneumo-enteritis,  or  typhoid  fever  of  the 
pig,  is,  like  splenic  fever,  due  to  a  Bacillus.  Having  succeeded  in 
cultivating  this  Bacillus  in  such  a  manner  as  to  raise  crops  free  from 
all  other  organisms.  Dr.  Klein  inoculated  healthy  pigs  with  the  fluid 
containing  the  Bacilli,  and  found  that  the  disease  in  due  time  arose 
and  followed  its  ordinary  course.  It  is  now,  therefore,  distinctly 
proved  that  two  diseases  of  the  higher  animals,  namely,  '  splenic 
fever  '  and  '  infectious  pneumo-enteritis,'  are  generated  by  a  contagium 
vivum. 

Finally,  Messrs.  Downes  and  Blunt  have  commenced  an  inquiry 
into  the  influence  of  light  ujjon  Bacteria  and  other  fungi,  which 
promises  to  yield  resiilts  of  great  interest,  the  general  tendency  of 
these  investigations  leaning  towards  the  conclusion  that  exposure  to 
strong  solar  light  checks  and  even  arrests  the  development  of  such 
organisms. 

The  practical  utility  of  investigations  relating  to  Bacillus 
organisms  as  aflbrding  to  the  pathologist  a  valuable  means  of  asso- 
ciating by  community  of  origin  various  diseases  of  apparently  different 


NOTES    AND    MEMORANDA.  71 

cliaractei',  is  exemplified  in  the  '  Loodiana  fever,'  which  has  been  so 
fatal  to  horses  in  the  East.  The  dried  blood  of  horses  that  had  died 
of  this  disease  in  India  has  been  recently  sent  to  the  Brown  Institu- 
tion, and  there  afforded  seed  from  which  a  crop  of  Bacillus  anthracis 
has  been  grown,  which  justified  its  distant  pathological  origin  by 
reproducing  the  disease  in  other  animals.  Other  equally  interesting 
experiments  have  been  made  at  the  same  Institution,  showing  that  the 
*  grains '  which  are  so  largely  used  as  food  for  cattle,  aff'ord  a  soil 
which  is  peculiarly  favourable  for  the  development  and  growth  of  the 
spore  filaments  of  Bacillus ;  and  that  by  such  '  grains '  when  in- 
spected, the  anthrax  fever  can  be  produced  at  will,  under  conditions  so 
simple,  that  they  must  often  arise  accidentally.  The  bearing  of  this 
fact  on  a  recent  instance  in  which  anthrax  suddenly  broke  out  in  a 
previously  uninfected  district,  destroying  a  large  number  of  animals, 
all  of  which  had  been  fed  with  grains  obtained  from  a  particular 
brewery,  need  scarcely  be  indicated."  * 

Method  of  representing  an  Object  from  Microscopic  Sections. — 
Whilst  working  on  the  central  nerve  system  of  the  crayfish,  Herr 
Krieger,  of  Leipzig,  adopted  the  following  method  of  obtaining  as 
clear  a  view  as  possible  of  the  internal  structure. 

The  ganglia,  after  being  hardened  and  stained,  were  imbedded  in 
paraffin,  and  cut  by  the  microtome  into  a  series  of  transverse  sections. 
For  every  section  the  position  of  the  object-slider  was  read  oft'  on  the 
scale  of  the  microtome.  When  a  satisfactory  series  of  sections  had 
been  made,  they  were  drawn  with  a  camera,  and  the  difterent  tissue- 
elements  (ganglia-cells,  nerve-fibres,  &c.)  were  marked  out  with 
difterent  colours.  Then  a  millimetre  scale  was  drawn  with  the  same 
amplification,  and  a  sheet  of  paper  ruled  with  parallel  lines  whose 
distance  aj)art,  according  to  this  scale,  was  equal  to  the  tliickness  of 
the  sections.  Each  of  the  drawings  was  then  orthograi^hically  pro- 
jected on  to  a  straight  line  drawn  parallel  to  the  transverse  axis  of  the 
section,  and,  when  the  direction  of  the  cut  was  exactly  at  right 
angles  to  the  longitudinal  axis  of  the  object,  each  projection,  according 
to  its  place  as  determined  by  the  readings  of  the  microtome  scale, 
was  marked  off'  between  the  parallel  lines  in  such  a  manner  that  the 
middle  points  of  the  projection  (symmetrical  on  both  sides)  fell  on  a 
straight  line  drawn  at  right  angles  to  the  parallel  lines.  Nothing 
more  has  now  to  be  done  but  to  connect  together  the  points  of  the 
projections  corresponding  to  the  outlines  of  the  various  structures, 
and  by  slight  shading,  &c.,  to  distinguish  between  those  lying  higher 
or  deeper,  in  order  to  get  a  representation  of  what  the  object  would 
look  like  if  it  were  perfectly  transparent  and  were  viewed  from  above. 
If  the  direction  of  the  cut  is  not  exactly  at  right  angles  to  the 
longitudinal  axis  of  the  object,  we  must  determine,  by  comparing 
the  unsymmetrical  halves  of  the  section  with  those  of  the  preceding 
and  following  ones,  the  angle  of  the  symmetrical  plane  to  that  of 
the  direction  of  the  cut — draw  the  central  line  so  that  it  forms  this 
angle  with  the  parallel  lines,  and  mark  off  the  projections  as  before. 

♦  '  Proc.  Roy.  Soc.,'  vol.  xxviii.  p.  43. 


72  NOTES   AND   MEMORANDA. 

By  horizontal  and  sagittal  sections,  as  also  by  measurements  of  the 
drawing  and  the  uncut  object,  the  results  obtained  may  be  checked. 

Though  this  plan  may  seem  somewhat  tedious,  the  author  says 
that  the  result  rej^ays  the  trouble,  as  so  plain  a  view  of  the  object 
examined  could  not  easily  be  obtained  in  any  other  way.* 

Microscopy  at  the  Paris  Exhibition. — It  seems  to  be  agreed  by 
those  who  visited  this  Exhibition  that  there  was  literally  nothing  new  or 
calling  for  special  remark  either  in  Microscopes  or  accessories.  Micro- 
scopes were  included  in  Class  15,  "  Instruments  of  Precision,"  whilst 
Class  8,  "  Methods  and  Material  of  Higher  Education,"  contained 
most  of  the  Microscopic  preparations  exhibited,  some  of  which  were 
also  included  in  Class  14,  "  Medicine,  Hygiene  and  Public  Assistance  ;" 
Class  12,  "Photographic  Apparatus  and  Photographs,"  contained 
Micro-photographs.  The  jurors  in  Class  15  were  Lord  Lindsay  (for 
England),  MM.  Bardoux,  Cornu  and  Laussedat,  and  Commandants 
Mouchez  and  Perrier  (for  France) ;  Dr.  Fleischl  (for  Austria-Hun- 
gary) ;  Signor  Colombo  (for  Italy) ;  M.  Broch  (for  Sweden  and 
Norway)  ;  and  M.  Soret  (for  Switzerland). 

We  have  endeavoured  to  compile  a  list  of  the  gold,  silver,  and 
bronze  medals  and  honourable  mentions  awarded  to  opticians  and 
others  for  Microscopes,  &c. ;  but  as  these  were  not  separately  classed, 
it  is  impossible  to  distinguish  with  complete  accuracy  the  cases  in 
which  the  award  was  made  for  Microscopes,  or  for  some  of  the  other 
instruments  exhibited  in  conjunction  with  them.  The  difficulty  would 
obviously  not  be  solved  by  taking  the  names  of  those  opticians  who  are 
makers  of  Microscopes  only,  and  under  these  circumstances  we  must 
leave  the  official  list  to  speak  for  itself. 

The  Generation  of  Gas  in  the  Protoplasm  of  living  Protozoa.— 

The  discovery  that  gas  is  generated  in  the  protoplasm  of  Arcella  under 
the  influence  of  volition,  and  serving  for  a  hydrostatic  purpose,f  gave 
rise  to  the  conjecture  that  other  Protozoa  living  free  in  water  might 
be  able  to  make  use  of  this  simple  means  of  vertical  motion.  Professor 
T.  W.  Engclmaun  says  J  that  his  occasional  attemj)ts  to  confirm  this 
supposition  have  led  to  a  positive  result  in  at  least  two  instances. 

He  found  on  the  surface  of  some  water  which  was  taken  from 
a  ditch  richly  covered  with  duckweed,  a  spherical  Sphoerojplirya, 
measuring  •  08  mm.  which  contained  a  large  air-bubble.  The  species 
was  distinguished  by  its  size,  and  also  by  thirty  to  forty  relatively 
very  long  ('12  mm.)  and  thin  suctorial  filaments  regularly  spread 
over  the  surface  of  the  body ;  and  also  by  numerous  small  con- 
tractile vesicles  placed  at  some  distance  under  the  cuticle.  It 
may  be  called  /^p7i.  hydrostatica.  When  the  animal  came  to  be  ex- 
amined, the  air-bubble  occupied  about  the  fourth  part  of  the  volume 
of  the  body,  it  was  situated  immediately  under  the  cuticle,  and  had  in 
a  tangential  direction  a  long  oval  shape.  In  four  minutes  it  disap- 
peared, decreasing  very  gradually,  and  at  the   same  time  becoming 

*  '  Zoologischer  Auzeiger,'  vol.  i.  p.  369. 

t  See  Pfliiger's  '  Archiv  fiir  die  ges.  Physiologie,'  vol.  ii. 

X  '  Zoologischer  Anzeiger,'  vol.  i.  p.  152. 


NOTES   AND    MEMORANDA.  73 

more  irregular  and  angular.  The  protoplasm  meantime  advanced 
from  within  towards  the  cuticle,  which  sank  in  somewhat  and  became 
folded.  The  original  spherical  form  of  the  animal  became  very 
sensibly  flattened.  Attempts  to  produce  a  fresh  generation  of  gas 
unfortunately  could  not  be  made. 

The  second  case  relates  to  a  form  allied  to,  if  not  identical  with 
Amoeba  radiosa.  It  was  obtained  by  a  pipette  from  the  surface  of  some 
water  pretty  thickly  covered  with  Lemna.  Amongst  several  specimens 
one  was  found  which  measured  about  •  15  mm.,  and  was  furnished  with 
about  twenty  short,  irregular,  and  pretty  broad  conical  protuberances, 
which  in  the  interior  contained  a  perfectly  spherical  air-bubble  about 
•  05  mm.  in  diameter.  This  continually  diminished  from  the  moment 
the  animal  came  to  be  examined.  Within  three  minutes  it  had  dis- 
appeared, and  he  did  not  succeed  in  observing  a  new  generation  of 
air. 

Since,  therefore,  the  presence  of  gas-bubbles  in  living  protoplasm 
has  been  confirmed  in  three  forms  of  Protozoa  lying  widely  apart 
from  each  other,  it  may  be  considered  probable  that  the  phenomenon 
is  still  further  extended ;  but  as  he  is  only  seldom  in  a  position  to  pay 
attention  to  the  subject,  Professor  Engelmann  asks  those  of  his  fellow 
explorers  in  the  same  field,  who  have  more  frequent  ojiportunities,  to 
investigate  the  matter.  Success  would  doubtless  be  best  attained  if 
the  animals  are  taken  from  the  surface  of  the  water  and  examined  as 
quickly  as  possible. 

On  this  communication  Professor  Geza  Entz,  of  Hungary, 
writes:* — "  Eeferring  to  the  account  given  by  Professor  Engelmann 
of  the  interesting  phenomenon  of  gas-bubbles  in  the  protoplasm  of 
Protozoa  swimming  on  the  surface  of  water,  I  have  had  an  oppor- 
tunity of  observing  it,  not  only  in  Arcella  and  Amoeba,  in  which  (espe- 
cially the  former)  it  occurs  with  great  frequency,  but  several  times  in 
Difflugia  proteiformis  also.  The  latter  had  always  only  one,  but  that 
a  very  large  gas-bubble,  occupying  almost  half  the  body ;  it  gradually 
diminished  whilst  under  examination,  finally  disappearing  without 
leaving  any  trace:  the  Arcella  Skudi  Amoeba,  on  the  other  hand,  often  had 
several  bubbles.  Once  I  observed  in  an  Arcella  a  bubble  between  the 
shell  and  the  body  of  the  rhizopod,  which  forced  itself  to  the  mouth  of 
the  shell  and  finally  out  from  beneath  it,  like  an  air-bubble  out  of 
a  submerged  tilted  bell.  It  should  be  observed  that  the  generation 
of  gas  in  the  protojolasm  of  Amoeba  and  Arcella  was  observed  thirty 
years  ago  by  Maximilian  Perty,  who  gave  the  same  explanation  of  the 
phenomenon  as  Engelmann." 

Sperm-formation  in  Spongilla. — The  presence  of  corpuscles  of  a 
zoospermatic  nature  in  Spongilla  appeared,  says  Dr.  C.  Keller,f  from 
Lieberkiihn's  researches  in  1856  to  establish  as  an  assured  fact  the 
existence  of  a  sexual  differentiation  in  the  sponges.  Since  then,  how- 
ever, the  investigation  of  marine  sponges  has  so  seldom  succeeded  in 
showing  the  spermatic  elements,  that  recently  serious  doubts  have 
been  raised  in  influential  quarters  as  to  the  sexual  differentiation — 

*  '  Zoologisclier  Anzeiger,'  vol.  i.  p.  248.  f  Ibid.,  p.  314. 


74  NOTES    AND    MEMOEANDA. 

doubts  which  must  certainly  now  be  considered  comj)letely  disposed 
of  after  the  proof  of  the  separation  of  the  sexes  in  Halisarca  and  in 
Aplysilla  sulfurea,  where,  according  to  F.  E.  Schulze's  investigations, 
male  and  female  elements  occur.  Further  observations  may  serve  to 
give  greater  weight  to  Schulze's  statement. 

Dr.  Keller  endeavoured  last  year  to  examine  the  facts  in  question 
in  Spongilla.  A  separation  of  the  sexes  seems  to  occur  in  this  fresh- 
water sponge  also — at  least,  he  found  all  through  the  summer  small 
specimens  which  contained  neither  eggs  nor  larvae,  but,  on  the  con- 
trary, were  closely  filled,  especially  in  the  spring,  with  sperm-follicles 
in  the  most  varied  stages  of  develoj)ment.  The  smaller  specimens  were 
attached  to  the  cases  of  the  larvae  of  Phrt/ganea,  and  in  these  were  found 
almost  invariably  sperm-balls.  It  is  just  these  which  must  be  espe- 
cially adapted  for  fecundation. 

The  spermatic  elements  are  enclosed  in  a  special  receptacle,  and 
when  mature  move  about  in  it  with  great  activity. 

Each  follicle  is  surrounded  by  numerous  cells  (nutritive  migratory 
cells).  If  a  mature  follicle  bursts,  or  if  it  is  made  to  burst  by  pressure 
on  the  covering  glass,  the  sperm-cells  disperse,  and  move  about  in 
large  numbers  (their  heads  disposed  towards  each  other)  for  hours  at 
a  time  with  great  briskness. 

In  the  younger  follicles  the  movement  is  wanting ;  the  contents 
are  numerous  closely-pressed  round  elements.  It  is  to  be  assumed 
in  the  case  of  Spongilla,  therefore,  that  the  sperm-follicle  with  its 
contents  originates  from  a  single  cell  by  continual  division. 

These  are  recommended  as  a  desirable  object  for  demonstration  in 
a  course  of  zootomy,  as  the  movements  in  the  follicles  last  a  con- 
siderable time.  The  small  Spongilla  found  attached  to  the  cases  of 
Phryganea  in  May  and  June  are  the  best  adapted  for  this  purpose. 

The  exact  Orientation  of  the  principal  Section  of  Nicols  in 
Polarizing  Apparatus. — It  is  sometimes  necessary  to  be  able  tj  de- 
termine the  orientation  of  the  lirincij^al  section  of  the  polarizers  and 
analyzers — Nicols,  double  refracting  prisms,  &c. 

It  may  be  done  simply  and  with  precision  by  illuminating  the 
apparatus,  in  order  to  adjust  it,  with  yellow  light,  and  interposing 
a  diaphragm  between  the  polarizer  and  analyzer,  oue-half  of  it  being 
covered  with  a  half  undulation  plate  of  thin  quartz  parallel  to  the 

axis. 

This  diaphragm  can  always  be  put  in  position.  Polarizing  appa- 
ratus generally  have  either  a  system  of  lenses  or  a  single  lens,  which 
can  then  be  used  to  view  the  diaphragm.  If  this  is  not  the  case,  a 
small  auxiliary  lens  can  be  used.  The  interior  margin  of  the  plate 
separates  the  two  half-disks,  and  produces  a  well-defined  line. 

Let  us  suppose  that  it  is  required  to  fix  a  Nicol  so  that  its  prin- 
cipal section  shall  make  a  given  angle  with  certain  reticular  threads, 
&c.  The  problem  is  reduced  to  placing  the  margin  of  the  plate  in  the 
desired  position,  and,  as  this  is  a  well-defined  line,  the  optical  and 
mechanical  means  are  not  wanting. 

The  Nicols  are  then  adjusted  with  respect  to  the  plate.  To  do 
this,  the  polarizer  is  placed  so  that  its  section  is  approximately  in  the 


NOTES   AND    MEMORANDA.  75 

required  direction,  and  the  analyzer  is  turned  a  few  degrees  to  the 
right  and  left.     Two  cases  then  present  themselves  : — 

1.  If  this  section  is  by  accident  exactly  in  the  required  position,  the 
transition  from  partial  to  total  extinction  will  be  gradual,  and  no 
difference  in  intensity  will  be  perceived  between  either  of  the  two  half- 
disks  in  any  position  of  the  analyzer. 

2.  If  the  section  of  the  polarizer  is  not  exactly  in  position,  if  it 
makes  even  an  excessively  small  angle  with  the  line  of  separation, 
variable  ditferences  will  be  found  between  the  two  half-disks. 

If  the  analyzer  is  stopped  in  a  position  near  to  total  extinction, 
one  half-disk  will  be  seen  to  be  darker  than  the  other ;  the  polarizer 
should  then  be  turned  gradually  till  equality  in  tint  is  established,  and 
that  will  be  the  position  sought.  This  should  be  tested  by  turnin^' 
the  analyzer,  when  the  two  half-disks  ought  to  be  found  perfectly 
equal  in  intensity,  this  intensity  varying  with  the  rotation  of  the 
analyzer. 

The  position  of  the  polarizer  is  marked ;  then  to  determine  that  of 
the  section  of  the  analyzer  the  polarizer  is  gently  displaced  about  1^°, 
which  destroys  the  equality  of  the  intensities ;  this  is  afterwards 
restored  by  the  analyzer.  The  principal  section  of  the  latter  will  be 
found  at  exactly  90^  from  this  last  position. 

This  method  can  also  be  used  to  determine  the  principal  sections 
of  quarter  and  half  undulation  plates,  and  that  of  plates  parallel 
with  the  axis.  It  gives  much  greater  precision  than  the  ordinary 
methods. 

The  margin  of  the  half-plate,  which  separates  the  two  half-disks, 
is  perfectly  clear,  and  without  thickness ;  we  have  then  to  compare 
two  surfaces  of  different  intensities  which  are  strictly  tangent.  If  the 
adjustment  is  made  with  care,  the  slightest  difference  will  be  appre- 
ciable ;  and  this  detail  contributes  much  to  increase  the  precision  of 
the  method.* 

Improvements  in  Object-glasses.— Mr.  Gundlach,  of  Rochester, 
New  York,  has  patented  a  method  of  constructing  object-glasses  for 
astronomical  telescopes  and  other  purposes,  by  which  both  aberrations 
are  corrected  to  a  higher  degree  than  has  hitherto  been  attained.  The 
common  double  objective,  consisting  of  a  negative  flint-glass  lens  and 
positive  crown-glass  lens,  is  deficient  by  reason  of  chromatic  over- 
correction at  the  outer  edge,  and  chromatic  under-correction  towards 
the  centre.  This  is  caused  by  the  flint-glass  lens,  as  usually  shaped, 
not  having  the  proper  form  to  remove  this  defect.  Nor  can  it  be 
perfectly  removed  by  any  alteration  in  shape,  except  at  the  expense  of 
increased  spherical  aberration,  the  correction  of  both  aberrations 
depending  on  the  same  factor  (the  flint-glass  lens),  and  on  opposite 
conditions  of  this  factor,  the  best  form  for  the  complete  correction  of 
the  one  producing  the  maximum  of  the  other  aberration. 

The  difficulty  is  obviated  by  constructing  an  object-glass,  in  which 

both  the  chromatic  and    the  spherical  aberrations  are  corrected  by 

special  means  independent  of  each  other,  leaving  the  flint-glass  lens 

to    perform   exclusively   its    legitimate   function    of   correcting   the 

*  M.  L.  Laurent,  in  '  Comptes  Kendus,'  vol.  Ixxxvi.  p.  662. 


76  NOTES  AND    MERIORANDA. 

chromatic  aberration  without  reference  to  the  spherical  aberration,  and 
correcting  the  latter  by  one  or  more  negative  crown-glass  lenses  of  the 
proper  focal  relations  to  the  others.  The  accompanying  drawing 
represents  a  cross  section  of  the  object-glass.  A  is  the  double 
concave  flint-glass  lens  ;  B  and  C  crown-glass  lenses,  of  appropriate 
focal  projiortions ;  and  D  an  additional  ne- 
gative crown-glass  lens,  its  purpose  being 
the  completest  correction  possible  of  the 
spherical  aberration.  The  double  concave 
form  is  the  best  for  the  highest  possible 
correction  of  the  chromatic  aberration,  the 
ordinary  concavo-convex  form  having  been 
adopted  only  as  a  compromise  aiming  at  the  correction  of  both  aber- 
rations at  the  same  time,  which  can  only  be  imperfectly  attained 
under  such  circumstances.  By  this  means  the  objective  can  be  made 
almost  absolutely  achromatic,  leaving  the  sjiherical  aberration  to  be 
corrected  by  other  and  independent  means,  viz.  by  tlie  sj)ecial  nega- 
tive crown-glass  lens,  D  (or,  if  preferred,  more  than  one),  concavo- 
convex  in  shape,  the  concave  surface  of  which  has  a  shorter  radius 
than  the  convex  surface  of  the  positive  crown-glass  lens  nest  to  it,  so 
that  between  the  two  a  space  remains  in  the  shape  of  a  meniscus. 

The  loss  of  illuminating  power  on  account  of  the  increased 
number  of  surfaces  can  be  reduced  to  a  minimum  by  cementing  the 
adjoining  surfaces ;  the  loss  being  further  reduced  in  comparison 
with  a  double  object-glass  by  having  the  outer  surfaces  consisting  of 
crown  glass,  the  loss  of  light  on  such  surfaces  being  less  than  on 
flint-glass  surfaces.  It  will,  moreover,  be  preponderatingly  com- 
pensated by  the  better  correction  of  the  aberrations  and  the  greater 
clearness  and  sharpness  of  definition  resulting  therefrom. 

British  Acari— Oribatidse. — Mr.  A.  D.  Michael  has  sent  a  paper 
to  the  Society  (which  cannot  be  published  yet  for  want  of  space) 
giving  the  results  of  his  researches  among  British  Acari  of  the  family 
Oribatidce,  conducted  during  the  past  year  in  conjimction  with  Mr.  C. 
F.  George.  Forty-four  species  have  been  found,  of  which  only  three 
or  four  have  been  previously  recorded  as  British.  Of  these  forty-four 
species,  three  are  believed  to  be  entirely  new,  viz.  two  species  of  the 
genus  Tegeocranus  which  Mr.  Michael  proposes  to  call  respectively 
T.  lahyrinthicus  and  T.  eloncjatus,  and  one  which  he  proposes  to  make 
the  type  of  a  new  genus  to  be  called  Scutovertex,  the  species  being 
called  sculptus.  The  new  species  are  fully  described  and  figured. 
The  life-history  of  Tegeocranus  latus,  Noilirus  tJieleproctus,  &c.,  of 
which  the  larvae  and  nymphs  were  not  previously  known,  have  been 
traced,  and  are  described  and  figured. 

The  Structure  of  the  Nerves  in  the  Invertebrata. — The  histolo- 
gical characters  of  the  nerves,  whilst  determined  with  precision  for  the 
Vertebrata,  are  imperfectly  known  in  the  other  divisions  of  the  animal 
kingdom.  Their  exact  determination  is  nevertheless  important  from 
all  points  of  view,  for  the  examination  of  the  external  form  alone  is 
insufficient  when  we  wish  to  know  if  such  or  such  part  among  inferior 


^  NOTES    AND    MEMORANDA.  77 

animals,  among  the  Sadiata  particularly,  belongs  or  not  to  the  nervous 
system.  Certain  authors,  moreover,  have  taken  their  stand  on  the 
diflferences  which  the  nerve  elements  present  in  Invertebrata  and 
Vertebrata  to  mark  further  the  separation  which  exists  between  these 
two  divisions  of  animals. 

The  nerves  of  Decapod  and  other  Crustacea,  in  spite  of  their  bulk, 
are  difficult  to  study,  by  reason  of  the  rapidity  with  which  these  elements 
alter  when  they  are  isolated  or  dead,  or  are  brought  into  contact  with 
any  reagent.  The  nerves  of  the  ganglionic  chain  and  the  peripheral 
nerves  jDresent  identical  characters.  They  are  formed  by  bundles  of 
nerve-tubes  enveloped  in  a  sheath  of  very  thick  perineurine. 

Each  of  these  tubes  is  composed  of  a  sheath  of  a  homogeneous 
amorphous  substance,  the  contents  of  which  are  soft,  easily  changeable, 
sometimes  homogeneous,  sometimes  either  finely  granular,  or  striated 
longitudinally.  These  tubes  are  very  volumLuous.  Their  diameter 
varies  from  -01  mm.  to  -08  mm.  and  -09  mm.  Notwithstanding  that, 
all  the  cylinder  of  the  substance  or  soft  fibre  which  fills  the  amorphous 
sheath  of  the  nerve-tubes  of  the  Crustacea  corresponds  to  the  single 
cylinder-axis  of  the  nerve-tubes  of  the  Vertebrata,  an  idea  already 
propounded,  but  in  a  rather  doubtful  manner,  by  Leydig.  The 
myeline  is  wanting,  and  its  absence  leaves  the  essential  microscopical 
filaments  of  the  nerves  with  their  transparency  and  their  paleness, 
whence  the  difficulty  of  seeing  them  by  transmitted  light  as  with  the 
naked  eye.  Our  *  researches  show  that  there  is  identity  of  substance 
between  the  cellular  body  of  the  ganglionic  cells  and  the  contents  of 
the  nerve-tube  starting  from  the  ganglia.  1st,  the  large  cells  of  the 
ganglia  which  attain  the  size  of  oue-fifth  to  one-fourth  of  a  millimetre, 
have  prolongations  very  nearly  as  large  as  the  largest  peripheral  nerve- 
tubes  into  which  we  succeeded  in  following  them,  as  so  many  fibres 
filling  the  tube  or  homogeneous  sheath ;  2ad,  immediately  after  death 
sarcodic  atoms  are  formed  in  the  cells  and  in  the  substance  of  the  nerve- 
fibres,  gradually  bringing  about  the  decomposition  of  both  into  granular 
masses  of  identical  appearance ;  3rd,  nitric  acid,  alum,  and  perchloride 
of  iron  produce  at  the  same  time  coagulation  of  the  body  of  the  cells 
and  the  contents  of  the  tubes.  Nitric  acid,  particularly,  gives  an 
absolutely  conclusive  reaction ;  it  retracts  the  substance  of  the 
nerve-fibres,  and  produces  a  very  distinct  and  regular  longitudinal 
striation ;  the  same  striation  is  seen  on  the  cells  and  their  immediate 
prolongations.! 

*  M.  Cadiat,  in  '  Coraptes  Rendus,'  vol.  Ixxxvi.  p.  1420. 

t  This  is  diflScult  to  demonstrate  among  the  Vertebrata ;  and  it  has  been 
Eought  for  in  many  ways,  becau-e  it  is  important  to  physiology  to  know  if  each 
cylinder  axis  is  a  bundle  of  nervous  conductors.  In  the  Crustacea,  particularly  in 
the  Uraiu  squi7iado,  this  situation  is  very  evident.  On  the  ganglionic  chain  of 
larva  of  Libelluki  are  found  nerve-tubes  identical  with  those  of  the  Crustacea. 
But,  in  the  insects,  the  sheaths  of  Schwann  are  very  fine  and  frao-ile,  and  under 
the  influence  of  the  least  pressure  or  of  a  liquid  having  sufficient  osmotic  power, 
all  the  tubes  enclosed  in  the  same  sheath  of  perineurine  break  and  leave  a  graimlar 
residue  scattered  over  with  nuclei.  This  granular  matter,  under  the  influence  of 
alum  and  carmine,  takes  exactly  the  same  tint  and  the  same  appearance  as  the 
masses  which  surround  the  nucleus  of  the  nerve-cells.  In  the  Leech,  Dytiscus, 
and  Hydrophiius  we  have  obtained  analogous  results. 


78  NOTES   AND   MEMORANDA. 

To  sum  up ;  among  the  Crustacea,  tlie  Insecta,  and  the  Annelida,  the 
structure  of  the  nerves  differs  from  that  of  the  Vertebrata  by  the  com- 
plete absence  of  the  substance  endowed  with  great  refractive  power, 
called  myeline,  which  in  these  latter  is  interposed  between  the 
cylinder-axis  and  the  proper  wall  of  the  tube,  the  grey  fibres  of  the 
great  Sympathetic  excepted. 

In  the  Gasteropodous  and  Acephalous  Molluscs  the  nerves  are 
further  simplified  ;  the  sheath  proper,  or  sheath  of  Schwann,  is  wanting 
in  almost  all  the  nerves.  The  nerve-tuhes  only,  represented  by  the 
cylinder-axis,  form  bundles  which  it  is  difficult  to  dissociate. 

One  more  character  remains  yet  to  be  added  to  those  which  we 
have  referred  to.  The  nerve-cells  of  Crustacea  were  of  an  extreme 
fragility.  The  contents  of  their  tube  are  displaced  very  easily.  In 
the  snail  the  cell  takes  a  certain  consistency.  The  cylinder-axis  of 
the  nerves  opposes  also  more  resistance  to  pressure  and  to  chemical 
agents. 

The  author  adds  in  a  further  foot-note  : — In  the  Bryozoa  we 
have  observed  a  nerve  layer  situated  under  the  ectoderm.  This  layer 
was  composed  of  cells  very  distant  from  one  another,  and  united  by 
bundles  of  rectilinear  filaments  possessing  small  oval  nuclei  in  their 
thick  part,  resembling  those  which  are  formed  in  the  nerve-fibres 
during  development  in  all  animals.  From  this  sort  of  plexus  start 
very  fine  threads  which  extend  along  the  tentacles,  others  go  to  the 
retractor  muscle.  The  characters  observed  in  the  nerve-tubes  of  all 
the  animals  which  we  have  passed  in  review  allow  us  to  conclude  that 
the  cells  with  the  filaments  which  depend  from  them,  and  which  we 
have  seen  in  the  Bryozoa,  are  truly  nerve  elements.  Here,  the 
nerves,  closely  allied  in  their  structure  to  those  of  the  Molluscs 
properly  so  called,  would  be  reduced  to  the  cylinder-axis. 

Development  of  Cephalodia  on  Lichens. — M.  Babikof  has  under- 
taken some  investigations  with  the  view  of  settling  the  origin  of  the 
peculiar  excrescences  found  on  the  surface  of  some  lichens,  known  as 
Cephalodia.  The  result  is  contained  in  a  paper*  presented  to  the 
Imperial  Academy  of  Sciences  of  St.  Petersburg. 

The  author  says  that  the  structure  of  the  cephalodia  is  known  in 
a  small  number  of  lichens  only,  and  that  there  are  but  few  exact 
notions  as  to  their  development-history.  Some  hypotheses,  very 
probably  correct,  have  been  suggested,  but  they  have  not  yet  been 
established  by  facts.  A  summary  is  given  of  the  views  of  Messrs. 
Nylander,  Th.  Fries,  Schwendener,  and  Bornet,  on  the  cephalodia  of 
Stereocaidon,  and  it  is  pointed  out  that  what  they  have  observed  has 
been  simply  different  degrees  of  development  of  the  alga  by  the  hypha, 
and  not  the  complete  progress  of  the  development  of  the  cephalodia. 

"  It  is  therefore  only  in  consequence  of  simple  isolated  facts  that 
the  authors  have  supposed  that  the  cephalodia  are  abnormal  forma- 
tions produced  by  a  local  growth  of  the  lichen  under  the  influence  of 
algaj  accidentally  fallen  upon  it.  Their  hypothesis  has,  however,  been 
completely  confirmed  by  experiments  which  I  have  made  under  the 
guidance  of  Professor  A.  S.  Famintzin,  on  the  development  of  the 
*  '  Bull,  de  rAoade'niie  des  Sciences  de  St.  Petersburg,'  vol.  xxiv.  p.  548. 


NOTES    AND    MEMOKANDA.  79 

ceiihalodia  of  PeUigera  aphthosa,  which  I  have  followed  from  the  first 
commencement  of  the  invasion  of  the  alga  by  the  hypha  ujj  to  the 
complete  development  of  the  cephalodia." 

After  a  reference  to  the  descrijjtion  given  by  Acharius  of  the 
cejihalodia  in  question,  the  author  thus  details  his  own  investiga- 
tions. 

In  vertical  sections  of  a  cephalodium  of  PeUigera  aphihosa  com- 
pletely developed,  the  central  part  consisted  of  a  tissue  of  filaments 
loosely  interlaced  with  hyjjha,  between  which  wore  masses  of  bluish 
gonidia,  arranged  without  any  apparent  order,  whilst  the  j^eriphery 
was  formed  of  a  homogeneous  brown  cortical  layer,  much  thicker  on 
the  superior  side  than  on  the  inferior,  and  consisting  of  pseudo- 
parenchymatous  tissue.  From  the  inferior  surface  descend  a  row  of 
radical  hairs  (rhizines)  of  a  dark  brown,  of  which  the  membranes,  very 
much  thickened,  penetrate  to  the  soil  through  the  openings  of  the 
thallus  of  Peltujera  and  interlace  themselves  with  the  similar  hairs  of 
the  latter.  The  body  itself  of  the  cephaludium  is  in  contact  with  the 
edges  of  the  opening  of  the  thallus,  like  a  cover,  and  without  any 
organic  relationship  with  it.  If  the  general  form  of  the  cephalodium 
were  examined,  w-ithout  knowing  the  history  of  its  development,  we 
should  suppose  that  it  must  be  a  homeomerous  lichen  growing  para- 
sitically  on  the  PeUigera  and  bearing  a  resemblance  to  Pannaria 
triptophijUa,  for  example.  The  gonidia  of  the  cephalodia  are  blue,  and 
consequently  belong  to  the  phycochromaceous  algas ;  whilst  those  of 
the  lichen  itself  are  of  a  light  green  and  belong  to  the  chlorophy- 
laceous.  They  are  also  distinguished  from  one  another  by  their  size  ; 
the  former  attain  -010  mm.,  the  latter  only  •006  mm.  Both  are 
oblong,  often  triangular  or  square,  but  rarely  round.  In  examining 
the  form  of  the  gonidia  of  the  cephalodia  it  is  impossible  to  decide  to 
what  algfe  they  belong. 

To  solve  this  question,  the  author  took  advantage  of  the  method 
of  culture  employed  by  MM.  Famintzin  and  Baranetsky,  in  their 
researches  on  the  gonidia  of  C  lUema  pulposum  and  PeUigera  canina, 
and  sowed  in  soil  previously  boiled  some  sections  of  cephalodia 
(examined  under  the  microscope  to  assure  the  absence  of  any  foreign 
organism),  and  then  placed  under  a  bell-glass  in  a  damp  atmosphere. 
At  the  end  of  two  weeks  and  a  half,  when  the  hyphae  were  entirely 
destroyed,  there  could  be  remarked  on  the  surface  of  the  sections  a 
great  number  of  small  gelatinous  balls,  each  containing  three  or  four 
bluish  cells.  After  another  week  the  little  balls  acquired  more  con- 
siderable dimensions,  and  the  number  of  bluish  cells  increased  ;  at  the 
same  time  these  latter  were  found  arranged  in  small  doubled  up  chains, 
of  which  some  already  contained  heterocysts  characteristic  of  Nosfoc. 
Five  weeks  after  the  sowing  colonies  of  perfectly  formed  Nosioc  were 
found,  which  consisted  of  numerous  little  chains,  with  completely 
developed  heterocysts  ;  the  little  chains  were  imbedded  in  a  mucilage 
bounded  by  very  distinct  outlines.  The  cultivation  of  the  gonidia 
proved  therefore  that  they  originated  from  the  Nostoc,  entirely  changed 
in  form  under  the  influence  of  the  invasion  of  the  hypha. 

Being  desirous  of  knowing  in  what  manner  perfectly  free  Nostoc 


80  NOTES    AND    MEMORANDA. 

had  degenerated  into  gonidia  and  had  given  rise  to  the  formation  of  the 
cephalodia,  the  author  examined  the  history  of  the  development  of  the 
latter  with  the  following  results  : — 

On  the  surface  of  the  thallus  of  Peltigera  apJithosa  are  found 
verrucose  ceiDhalodia,  which,  as  they  approach  the  edge  of  the  lichen, 
become  smaller  and  at  last  appear  to  the  naked  eye  like  a  grain  of 
dust.  The  smallest  are  the  youngest.  Amongst  these  excrescences  is 
often  found  a  bluish  coating,  which  consists  exclusively  of  Nostoc  in 
different  degrees  of  development ;  they  are  rarely  found  mixed  with  other 
algfe.  By  making  transverse  sections  of  the  youngest  portions  of  a 
perfectly  fresh  lichen,  it  may  be  seen  under  a  high  magnifyinc;  power 
that  its  surface  is  covered  with  a  great  number  of  hairs,  formed  of  one, 
two,  or  three  cells ;  among  these  hairs  are  often  found  whole  colonies 
of  Nostoc,  some  of  which  are  entirely  free,  simply  in  contact  with  the 
surface  of  the  hairs,  and  easily  separating  from  them  under  the 
pressure  of  the  covering  glass ;  others,  on  the  contrary,  are  so  closely 
attached  to  the  hairs,  that  it  is  only  by  very  strong  pressure  that  they 
can  be  detached,  and  then  only  by  removing  the  hair  at  the  same  time. 
The  hairs  connected  in  this  manner  with  the  colonies,  undergo  a 
division  into  numerous  cells,  and  put  out  little  branches  which  pene- 
trate into  the  interior  of  the  mucilage  and  wind  about  among  the 
filaments  of  the  isolated  Nostoc.  This  is  the  beginning  of  the  forma- 
tion of  the  cephalodia.  In  the  same  sections,  or  in  others  made  on 
older  portions  of  the  lichen,  colonies  of  Nostoc  are  met  with  where  the 
interlacing  by  the  hypha  begins.  We  see  distinctly  that  some  of  the 
branches  insinuate  themselves  into  the  interior  of  the  mucilage,  whilst 
others  only  touch  the  surface  and  give  rise  to  the  cortical  layer  by 
forming  numerous  lateral  branches  which  adhere  to  one  another.  At 
this  period  the  cortical  layer  does  not  cover  the  whole  surface  of  the 
colony  ;  the  mucilaginous  substance,  which  has  become  darker,  is  seen 
projecting  here  and  there,  and  in  the  interior  the  cells  of  Nostoc 
spread  themselves,  no  longer  arranged  in  the  form  of  isolated  filaments, 
but  united  into  a  compact  mass.  If  this  preparation  is  broken  up, 
there  will  be  seen,  amongst  the  cells  of  Nostoc,  filaments  of  hypha 
which  start  from  the  cells  of  the  cortical  layer.  In  sections  made  on 
an  older  portion  of  the  lichen,  colonies  of  Nostoc  are  found  entirely 
interlaced  by  hypha,  where  the  cortex  is  formed  of  a  continuous  layer 
of  cells,  arising  from  the  ramification  and  their  reciprocal  adherence. 
At  the  first  glance  such  formations  might  be  taken  for  the  fructifica- 
tions of  Pyrenomycetes,  if  the  history  of  their  development,  as  well  as 
their  anatomical  structure,  were  not  already  known. 

In  proportion  as  the  invasion  of  the  Nostoc  by  the  hypha  becomes 
complete,  the  cells  of  the  cortical  layer  of  the  lichen  and  the  hyphfe 
of  the  gonidial  layer  rise  considerably  in  their  growth,  and  gradually 
form  with  the  cephalodium  a  continuous  tissue.  The  gonidia  of  the 
lichen,  which  are  found  below  the  cephalodium,  perish  and  disappear 
gradually,  being  absorbed  by  the  surrounding  tissue ;  moreover  they 
are  no  longer  arranged  in  a  continuous  layer,  but  an  intermittent  one. 
In  its  more  advanced  stage,  the  cephalodium  increases  considerably  in 
a  direction  parallel  to  the  surface  of  the  lichen  and  takes  a  lenticular 


K0TE3   AND    MEMORANDA.  81 

form.  It  is  in  this  stage  that  it  is  described  and  figured  by  Acha- 
rius  (t.  X.  f.  8).  When  the  ceplialodium  so  increases,  the  tissue 
of  the  lichen  under  it  no  longer  appears  in  the  form  of  pseudoparen- 
chymatous  cortex,  and  no  longer  encloses  gonidia,  but  consists  only  of 
hyphae  very  much  interlaced,  and  it  is  only  on  the  parts  placed  near 
the  borders  of  the  cejihalodium,  that  there  can  still  be  observed  a 
progressive  transition  of  the  round  cells  of  the  cortex  into  the  com- 
pletely developed  filaments  of  the  hypha,  which  degenerate  progres- 
sively into  radical  hairs  (rhizines)  of  a  dark  brown  colour.  As  soon 
as  the  final  transformation  of  the  tissue  of  the  bark  of  the  lichen  into 
filaments  of  hypha  is  accomplished,  all  connection  between  the  cepha- 
lodium  and  the  thallus  of  the  lichen  disappears.  At  the  point  where 
the  separation  of  the  cephalodium  has  taken  place,  the  cells  of  the 
cortical  layer  of  the  lichen  assume  a  brown  hue ;  below  them  extends 
a  layer  of  gonidia  which,  whilst  it  touches  some  of  the  radical  hairs 
of  the  cephalodium,  has  no  longer  any  connection  with  them.  Under 
the  layer  of  the  gonidia  of  the  thallus  is  arranged  the  medullary 
layer,  whose  filaments  are  clearly  distinguished  from  the  radical  hairs 
by  their  more  transparent  colour,  as  well  as  by  the  thickness  of  their 
membrane.  The  cells  of  the  hypha  of  the  cephalodium,  disposed 
under  its  gonidia,  having  degenerated  into  radical  hairs,  are  trans- 
formed into  pseudoparenchymatous  cortex  which  covers  its  inferior 
face.  As  soon  as  the  cephalodium  becomes  entirely  independent  of 
the  lichen,  it  grows  more  and  more  horizontally,  and  finally  receives 
the  oblong,  or  orbicular  and  flattened  form. 

We  may  conclude  that  the  cephalodia  owe  their  origin  to  the 
parasitic  nature  of  Nostoc,  which  is  always  found  in  damp  places, 
where  the  lichen  is  usually  met  with.  Not  that  the  Nostoc  alone 
takes  part  in  the  formation ;  other  algfe  also  share  in  it  perhaps,  as 
Schwendener  and  Bornet  have  shown  in  Stereocaulon.  It  is  possible, 
that  if  Peltigera  aphthosa  were  gathered  in  some  other  locality,  other 
algfe  than  Nostoc  might  perhaps  also  be  found.  A  coloured  plate  of 
nine  figures  accompanies  the  paper. 

Mr.  Soiby's  New  Micro-spectroscope. — This  instrument,  which 
was  briefly  noticed  in  its  original  form  at  page  148  of  vol.  i.,  has 
since  been  modified  and  improved,  and  was  exhibited  at  the  meeting 
of  the  Society,  on  8th  January. 

The  principal  advantages  of  the  instrument  are  the  small  size 
(half  the  ordinary  size)  combined  with  great  dispersive  power  and 
excellent  definition,  with  large  field  of  view  over  the  whole  spectrum. 

To  obtain  this,  a  change  in  the  ordinary  mode  of  construction  has 
•been  adopted,  the  achromatic  object-glass  focussing  the  slit  being 
placed,  not  below  the  prism  as  usual,  but  above  it,  close  to  the  eye, 
A  much  longer  focus  can  therefore  be  obtained  for  the  object-glass, 
and  consequently  better  definition.  To  collect  the  light  coming 
from  the  slit,  a  cylindrical  lens  is  fitted  behind  the  prism  and  gives  an 
even,  bright  light  far  into  the  extreme  ends  of  the  spectrum,  so  that 
no  shifting  of  slit  or  micrometer  arrangement  is  required.  Without 
any  trouble  of  re-adjustment  the  object-glass  also  focusses  a  micro- 
meter scale  which  extends  over  the  whole  spectrum,  and  consequently 

VOL.  ir.  Or 


82  NOTES   AND    MEMORANDA. 

wave-lengtlis  can  be  read  off"  with  ease  in  every  part.  The  compari- 
son prism  is  placed  at  right  angles  to  the  line  of  the  slit,  and  enables 
both  spectra  to  be  focussed  sharjily  at  one  and  the  same  time. 

Mr.  Hilger,  by  whom  it  is  made,  calls  it  "  the  Miniature  Micro- 
spectroscoi)e." 

The  Structure  of  Blood-vessels. — Eanvier*  has  described  peculiar 
spindle-shaped  extensions  in  the  blood-vessels  of  the  red  muscles  of 
rabbits — a  kind  of  small  aneurism.  They  are  found  in  the  capillaries, 
esj^ecially  where  they  merge  into  each  other,  and  in  small  veins. 
These  extensions,  according  to  Eanvier,  are  the  reservoirs  for  blood, 
from  which  the  muscles  at  the  moment  of  contraction  draw  oxygen. 

These  extensions  of  the  blood-vessels  are  not  only  found  in  red 
muscle,  but  also  in  other  contractile  tissues.  Professor  P.  Peremeschko 
says  f  that  he  has  found  them  finely  developed  in  the  Lig.  nuchas  of 
dogs  and  cats.  They  are  situated  chiefly  in  the  capillaries,  but  also 
in  small  arteries  and  veins.  Their  number  is  much  more  considerable 
here  than  in  muscle  ;  they  are  often  placed  in  one  and  the  same 
vessel  in  rows  alongside  of  each  other,  so  that  the  injected  vessel 
assumes  the  form  of  a  string  of  jiearls.  Their  shape  is  sometimes 
spindle-like,  sometimes  oval,  sometimes  quite  round.  In  young 
animals  their  length  and  thickness  and  number  are  less  than  in  full- 
grown  animals.  In  embryos  during  the  first  half  of  gestation  they 
are  entirely  wanting,  and  appear  only  at  the  end  of  that  pei'iod  in  the 
form  of  scarcely  recognizable  thickening  of  the  vessels. 

Borings  of  a  Sponge  in  Marble. — Some  fragments  of  white 
Italian  marble  were  recently  presented  to  the  Peabody  Museum  of 
Yale  College,  U.S.  The  marble  was  part  of  a  cargo  wrecked  off"  Long 
Island  in  1871,  and  taken  up  in  1878.  The  exposed  portions  of  tlie 
slabs  were  thoroughly  penetrated  to  the  depth  of  one  to  two  inches 
by  the  crooked  and  irregular  borings  or  galleries  of  tlie  sponge  Cliona 
sulphurea,  Verrill,  so  as  to  reduce  it  to  a  complete  honeycomb,  readily 
crumbling  in  the  fingers.  Beyond  the  borings  the  marble  was  per- 
fectly sound  and  unaltered.  The  rapid  destruction  of  the  shells  of 
oysters,  &c.,  by  the  boring  of  this  sponge  has,  Mr.  Verrill  says,|  been 
long  familiar  to  him,  but  of  its  efiects  upon  marble  or  limestone  he 
has  not  before  seen  examples  ;  for  calcareous  rocks  do  not  occur 
along  the  portion  of  the  American  coast  which  it  inhabits.  Its  ability 
to  rajDidly  destroy  such  rocks  might  have  a  practical  bearing  in  case 
of  submarine  structures  of  limestone  or  other  similar  materials. 

Alcoholic  Fermentation. — M.  Pasteur  has  carried  out  his  inten- 
tion of  making  a  critical  examination  of  the  MSS.  of  the  late  Claude 
Bernard.§  which  M.  Berthelot  stated  contained  a  refutation  of  M. 
Pasteur's  theories.  The  result  of  this  examination  is  published  in 
No.  22  of  the  last  volume  of  the  '  Comj)tes  Eendus,'  ||  where  it  occuj)ies 

*  '.Arch,  de  Physiol.,'  1874,  t.  1. 

t  '  Zoologischer  Anzeiger,'  vol.  i.  p.  200. 

%  'Am.  Jour,  of  Sci.  and  Arts,'  vol.  xvi.  p.  406. 

§  See  vol.  i.  p.  271. 

II  '  Comiites  Rendus,'  vol.  Ixxxvii.  p.  813. 


NOTES   AND    MEMOEANDA.  83 

six  pages.  M.  Pasteur  describes  the  MSS.  as  "  one  of  the  most  curious 
revelations  possible  of  the  influence  of  a  defective  system  on  a  person 
extremely  exact  and  given  to  rigorous  experimentation.  It  is  a  sterile 
attempt  to  substitute  for  well-established  facts  the  deductions  of  an 
ephemeral  system.  The  glory  of  our  illustrious  confrere  cannot  be 
diminished  by  it.  The  errors  of  tbose  who  have  accomplished  a 
valiant  career  have  only  the  philosophic  interest  which  belongs  to 
the  recognition  of  oiu*  human  weakness.  Men  are  great  only  by  the 
services  which  they  have  rendered,  a  maxim  which  I  am  happy  to 
borrow  from  Bernard's  last  words." 

Dry  Preparations  of  Diatoms,  «S:c. — Although  there  are  many 
processes  for  making  balsam  jjreparations  of  very  thin  objects  which 
are  required  to  be  placed  in  the  most  favourable  position  lor  observa- 
tion, or  in  a  particular  order,  yet  few  are  able  to  accomplish  this 
readily  in  the  case  of  dry  preparations  except  M.  Moller,  whose  process 
is  a  secret. 

The  following  is  said  by  M.  G.  Marmod  in  the  'Journal  de 
Micrographie '  *  to  be  a  very  simple  method.  Heat  a  small  quantity 
of  oil  of  cloves,  and  expose  a  slide  to  the  vapour  until  there  is  deposited 
on  the  slide  a  series  of  very  small  drops.  These  drops  take  an  hour 
or  two  to  evaporate  completely,  and  there  is  therefore  plenty  of  time 
to  arrange  the  diatoms  or  other  objects,  which  will  remain  after  the 
evaporation  solidly  fixed  and  without  deposit. 

The  Organs  of  Attachment  of  Stentors. — From  an  examination 
of  Stentor  cceruleus,  Professor  A.  Gruber  has  succeeded  f  in  finding 
out  how  these  animals  eifect  an  attachment  to  foreign  objects.  He 
agrees  with  Stein  J  that  a  suctorial  disk  is  never  found,  althouf^h 
sometimes  a  slight  disk-shaped  dejiression  is  seen  at  tlie  posterior 
extremity  of  the  body,  but  disagrees  with  Stein's  further  statement, 
that  the  attachment  is  effected  by  means  of  "  very  fine  pseudopodia- 
like  processes "  of  the  sarcode,  which  radiate  thickly  from  the 
posterior  pole  of  the  body  and  appear  like  a  skein  of  elongated  bristle- 
shaped  cilia.  No  structure  of  that  kind  was  found  in  S.  cceruleus, 
though  vibratile  cilia  were  seen  which  were  longer  than  the  rest,  and 
which  doubtless  gave  rise  to  Stein's  descrij)tion. 

In  all  Stentors  there  are  to  be  found  immediately  after  they  have 
detached  themselves,  variously  shaped  small  appendages  at  the 
posterior  extremity  of  the  body,  which  on  closer  examination  prove  to 
be  amoeboid  processes  of  the  sarcode.  When  the  animal  has  no 
opportunity  of  attaching  itself  these  processes  disappear,  for  the  most 
part  somewhat  rapidly,  after  repeatedly  changing  their  form,  and  the 
end  of  the  pedicle  appears  uniformly  rounded.  On  the  other  hand 
in  the  case  of  an  animal  which  has  found  an  object  to  which  it  can 
attach  itself,  it  is  seen  that  the  processes,  mostly  finger-shaped  or 
drawn  out  into  fine  pseudopodia,  are  clasjjed  round  the  object. 

If  the  view  of  Stein  were  correct,  that  the  muscle-stripes  of  the 

*  '  Jourual  de  Micrographie,'  vol.  ii.  p.  506. 

t  '  Zoologischer  Anzeiger,'  vol.  i.  p.  390. 

X  'Der  Organismus  tier  Infus  ,'  II.  Abth.  p.  224. 

G    2 


84  NOTES   AND    MEMORANDA. 

Stentor  are  continued  to  the  posterior  pole  of  the  boily,  it  would  be 
difficult  to  conceive  how  these  fluid  amoeboid  processes  could  be 
formed  from  the  cortical  layer  to  which  the  muscles  belong.  Gruber 
saw,  however,  that  the  muscle-stripes  do  not  converge  to  the  pole,  but 
that  a  small  space,  which  forms  the  posterior  extremity  of  the  body 
(probably  the  disk-shaped  cavity  of  Stein)  remains  free  from  them. 

Here  the  structureless  sarcode  appears  therefore  in  its  natural 
state,  as  can  be  seen  when  the  part  is  viewed  from  above.  Though 
this  in  different  states  of  contraction  may  change  very  much  in  size 
or  even  almost  disappear,  yet  it  always  is  there  and  can  send  out 
pseudopodia  at  any  moment.  In  this  way  an  explanation  is  found  as 
to  how  those  amoeboid  processes  originate,  which  render  it  possible 
for  the  Stentor  to  attach  and  again  detach  itself  at  will. 

A  new  Method  of  preparing  a  Dissected  Model  of  an  Insect's 
Srain  from  Microscopic  Sections.— At  the  meeting  of  the  Quekett 
Microscopical  Club  of  the  24th  January,  Mr.  E.  T.  Newton  described 
a  very  ingenious  method  which  he  had  devised.  The  brain 
modelled  was  that  of  the  common  cockroach  (Blatta  orientalis),  and 
the  method  was  as  follows  : — The  brain  properly  hardened  was  cut  up 
into  a  consecutive  series  of  slices,  each  being  mounted  and  numbered. 
An  enlarged  drawing  of  each  section  was  then  made  with  a  camera 
lucid  a,  and  these  drawings  transferred  to  pieces  of  wood  of  a  thickness 
proportionate  to  the  thickness  of  the  sections,  and  then  cut  out  with  a 
saw.  By  piling  together  in  their  relative  positions  this  series  of  slices 
of  wood  and  ti'imming  off  the  angles,  a  model  of  the  external  form  of 
the  brain  was  produced  which  can  be  taken  to  pieces  so  as  to  show  the 
drawings  of  the  sections  upon  their  faces.  The  series  of  slices  which 
make  up  the  right  half  of  the  brain  were  then  taken  and  the  more 
important  structures  in  each  cut  out  like  a  child's  dissected  map  puzzle. 
The  corresponding  structures  were  taken  from  each  slice  and  fixed 
together  in  their  relative  positions,  in  such  a  manner  that  the  whole 
may  be  fitted  together,  and  when  desired  the  more  important  jjarts 
may  be,  as  it  were,  dissected  out.  The  President  (Professor  Huxley) 
highly  commended  the  ingenuity  of  the  method  and  the  manner  in 
which  it  had  been  given  effect  to  in  the  modjl — an  expression  of 
approval  which  was  fully  endorsed  by  the  meeting. 

The  Relations  of  Rhabdopleura. — This  singular  Polyzoal  genus 
was  the  subject  of  a  communication  by  Professor  Allman,  Pres.  L.  S.,  at 
the  meeting  of  the  Liuueau  Society  of  the  19th  December.  He  main- 
tains that  the  endocyst,  hitherto  supposed  absent,  is  really  represented 
by  the  contractile  cord  which  seems  to  take  the  place  of  the  funi- 
culus in  the  fresh-water  Polyzoa.  In  Rhabdopleura  the  endocyst  has 
receded  from  the  ectocyst,  and  its  wall  ajjproximation  and  nearly  com- 
plete obliteration  of  cavity  has  become  changed  into  the  contractile 
cord.  Anteriorly  it  spreads  over  the  alimentary  canal  of  the  polypide, 
to  which  it  becomes  closely  adherent,  and  here  represents  the  tenta- 
cular sheath.  Posteriorly  the  endocyst  undergoes  greater  modification, 
the  contractile  cord  becomes  chitinized,  and  converted  into  the  firm 
rod  which  runs  through  the  stem  and  branches  over  all  the  older  parts 
of  the  colony,  and  which  still  presents  in  its  narrow  lumen  a  trace  of 


NOTES   AND    MEMORANDA.  85 

the  origiiical  cavity  of  the  endocyst.  The  very  remarkable  shield-like 
a2)j)endage  which  is  attached  to  the  lophophore  G.  0.  Sars  regards  as 
epistome.  Professor  Allman  traces  its  development  as  a  primary  bud 
from  the  modified  endocyst,  and  it  again  budding  the  latter  finally 
becomes  the  definitive  polypide,  while  the  j)rimary  bud  remains  as  but 
a  subordinate  appendage.  We  have  thus  in  Rhabdopleura  an  altera- 
tion of  heteromoi'phic  zooids. 

Formation  of  Ovisacs  in  Copepoda. — In  a  recent  work  (on  two 
fresh-water  Calanidae)  Dr.  Gruber,  of  Freiburg,  in  Baden,  expressed  the 
conjecture  that  in  some  Copepoda  the  secretion  for  the  formation  of 
the  peculiar  (so-called)  ovisacs  consisted  in  part  of  the  emptied  contents 
of  the  adherent  spermatophore.  He  now  finds  *  that  this  is  not  so,  as 
he  intends  to  show  in  a  subsequent  publication  on  the  structure  of 
the  sexual  organs  and  the  reproduction  of  Copepoda.  The  secretion 
originates,  as  is  seen  in  Diaptomus,  in  the  oviduct  itself,  and  is  forced 
out  by  the  eggs  on  their  exit  through  the  sexual  opening,  and,  being 
hardened  in  the  water,  forms  the  sac.  He  has  also  demonstrated  the 
existence  of  a  secretion  in  Cyclops  filling  the  oviduct  up  to  the  vulva, 
which  certainly  has  the  same  object. 

The  Conidia  of  Polyporus  sulfureus,  and  their  Development— 
M.  de  Seynesf  has  discovered  in  Polyporus  sulfureus,  Bull,  the  pre- 
sence of  secondary  organs  of  reproduction. 

A  specimen  of  this  fungus,  gathered  in  the  forest  of  Fontainebleau, 
presented  in  the  superior  part  of  the  receptacle,  which  usually 
becomes  white,  a  light  drab  tint  and  a  very  evident  pulverulent  state. 
Examined  under  the  microscope,  the  coloured  tissue  disaggregated 
into  a  considerable  number  of  small,  rounded,  free  bodies,  composed  of 
an  envelope,  thick,  smooth,  and  refractive,  and  with  contents  consist- 
ing almost  wholly  of  an  oily  homogeneous  nucleus,  separated  from  the 
wall  by  a  thin  layer  of  hyaline  liquid.  They  are  spherical,  with  a 
tendency  to  become  cruciform  or  oblong,  and  measure  from  •  005  mm. 
by  '006  mm.  to  '016  mm.  by  '019  mm.  A  certain  number  of  them 
are  borne  by  the  elongated  cells,  whose  structure  is  the  same  as  those 
of  the  cells  which  form  the  pseudoparenchyma  of  the  receptacle. 
These  cells  are  cylindrical  and  have  a  thick  refractive  wall,  sometimes 
quite  obliterating  their  internal  cavity.  The  ramifications  branch  off 
usually  at  right  angles,  and  they  present  sudden  inflexions  ;  these 
characters  are  so  clear  that  they  cannot  be  confounded  with  any 
mycelium.  We  cannot  then  conclude  that  we  have  to  do  here  with  a 
parasitic  vegetation  originating  from  the  exterior.  The  situation  of 
these  little  bodies  at  the  antipodes  of  the  sporiferous  tubes  on  the  in- 
terior of  the  receptacle,  gives  rise  to  a  legitimate  comparison  with  the 
conidia  of  the  receptacle  of  Fistidina  hepatica.  Thus  we  find  extended 
to  the  genus  Polyporus  an  anatomical  and  physiological  arrangement 
which  might  seem  to  be  confined  to  a  genus  of  mixed  characters, 
and  exceptional  in  many  respects. 

The  existence  of  endocarpous  conidia  in  P.  sulfureus  reveals  an 
unexpected  affinity  between  the  Polyporei   and  the    Lycoperdoidese. 

*  '  Zoologischer  Anzeiger,'  vol.  i.  p.  247. 
t  '  Coniptes  Rendus,'  vol.  Ixxxvi.  p.  805. 


8G  NOTES    AND   MEMORANDA. 

Here  we  have,  in  reality,  a  Polyporns  of  which  the  receptacle  is  angio- 
carporis,  like  that  of  tli  Gasteromycetes  in  the  superior  and  conidian 
part,  and  which  is  gymnocarpous  in  the  inferior  and  hymenial  part. 
This  receptacle  becomes  dry  and  brittle ;  the  whole  of  the  couidia 
in  it  have  at  maturity  the  appearance  of  a  pulverulent  gleba  much  more 
marked  than  in  Fistulina.  These  elongated  cellules  scattered  across 
this  sort  of  gleba,  produce  the  illusion  of  a  capillitiura. 

The  formation  of  the  conidia  is  successive ;  it  takes  place  at  the 
extremity  of  the  cellular  ramifications  ;  when  a  conidium  has  arrived 
at  maturity  and  is  detached,  a  second  is  formed  below,  and  detached 
in  its  turn.  This  is  the  process  of  development  which  authors  have 
called  "  acrosporous  "  ;  but  here,  as  in  the  greater  number  of  similar 
cases,  there  is  only  an  illusory  appearance.  Even  on  a  dry  specimen 
it  is  easy  to  recognize  the  real  genesis  of  the  couidia  by  unequivocal 
signs,  and  by  the  aid  of  appropriate  reagents.  In  the  greater  number 
the  envelope  is  homogeneous  and  single  ;  we  find  some,  however, 
especially  among  the  largest  ones,  which  have  empty  spaces  in  the 
thickness  of  the  wall  itself;  these  spaces  describe  a  curve,  concentric 
with  the  double  outline  of  the  wall,  and  are  situated  at  the  two  ex- 
tremities of  the  longer  diameter.  They  are  sometimes  united  by  a  dark 
line  which  traces  thus  the  separation  of  two  distinct  envelopes.  We 
can  see  that  the  outlines  of  the  external  enveloi^e  are  continuous  with 
those  of  the  parent  cell.  When  the  conidium  is  still  adhering  to  it, 
tlie  relatively  great  thickness  of  the  different  walls  renders  this 
observation  easy  and  its  interpretation  very  clear.  A  transversal 
septum  is  most  often  formed  below  the  point  at  which  the  conidium 
developes  itself,  so  as  to  form  a  chamber — a  sporangium,  it  may  be 
called — in  which  the  conidium  is  organized.  The  wall  of  the  latter 
adheres  early  to  that  of  the  parent  cell,  of  which  sometimes  it  does 
not  reach  the  summit ;  at  other  times  the  adherence  is  interrupted, 
and  even  the  si)ace  comprised  between  the  inferior  part  of  the 
conidium  and  the  septum  of  the  parent  cell  is  filled  with  cellulose. 
The  parent  cell,  impoverished  and  attenuated  below  the  sejitum, 
breaks  at  this  point,  and  the  conidium  carries  with  it  the  little 
cellulose  appendage  which  served  it  as  support.  Sulphuric  acid  and 
the  prolonged  action  of  glycerine  disassociate  the  conidium  from  the 
parent  cell  and  make  it  appear  free  from  all  adherence  in  the  cellular 
chamber  in  which  it  has  had  its  orig'n  ;  the  preliminary  phases  of  the 
germination  produce  the  same  result. 

We  have  seen  above  that  during  the  development  of  the  conidium 
the  wall  of  the  parent  cell  becomes  thinned  for  the  benefit  of  the 
conidium  ;  the  same  jDhenomenon  is  produced  in  the  successive  de- 
velopment of  the  cells  of  the  recejitacle  ;  these  facts  led  the  author  to 
examine  the  influence  which  is  exercised  on  the  properties  of  the 
fungoid  cellulose  by  the  displacements  which  it  undergoes  in  the 
species  which  take  u]}  from  the  thick  walls  of  their  cells  the  materials 
for  their  nutrition  and  growth.  The  instability,  the  diminution  of 
cohesion,  doubtless  imposed  on  the  fungine  by  these  displacements, 
seem  to  account  for  its  jjroperty  of  turning  blue  on  the  contact  of 
an  iodine  reagent,  without  becoming  soluble  in  Schweitzer's  liquid. 


NOTES   AND    MEMORANDA.  87 

It  miglit  be  said  to  pass  through  conditions  more  nearly  allied  to 
starch  or  to  dextrine  than  to  pure  cellulose.  Observations  made  on 
P.  sulfiireus  and  on  several  receptacles  of  Polypori,  on  Ptychogaster 
albus,  &c.,  have  shown  the  frequency  of  the  blue  or  red  reaction  of 
iodine  with  fungine,  contrary  to  what  has  been  admitted  hitherto. 
The  cause  of  this  apparent  contradiction  doubtless  consists  in  the 
physiological  phenomena  here  alluded  to.  It  is  worthy  of  remark 
that  the  organs  on  which  was  first  observed,  as  a  sort  of  anomaly, 
the  blue  reaction  of  iodine,  belonged  to  the  reproductive  system,  that 
is  to  say,  to  the  cellular  elements  of  most  recent  formation. 

Polarizer  for  the  Microscope. — At  the  meeting  of  the  Physical 
Society  on  9th  November,  Professor  W.  Gr.  Adams,  the  president, 
explained  a  simple  appliance  made  by  Mr.  S.  C.  Tisley  for  exhibiting 
the  coloured  bands  due  to  interference  with  thick  plates.  The  bands 
due  to  regular  reflection  and  refraction  were  produced  by  two  thick 
plates  nearly  parallel  to  each  other  and  fixed  in  a  brass  box  with 
rectangular  apertures  on  its  flat  faces  so  that  the  light  fell  on  the 
first  plate  at  an  angle  of  60°,  the  whole  apparatus  being  of  a  con- 
venient size  for  the  w\aistcoat  pocket.  The  elliptical  interference 
bands,  due  to  the  scattering  or  diffusion  of  light  at  a  point  on  the 
front  sui'face  of  one  of  the  plates,  were  shown  by  means  of  a  precisely 
analogous  arrangement,  except  that  the  inclination  of  the  plates  to 
each  other  was  somewhat  greater ;  in  this  case  the  interference  bands, 
formed  by  regular  reflection  and  refraction,  fall  in  another  direction, 
so  that  they  are  not  received  by  the  eye ;  the  diffusion  interference 
fringes  obtained  were  clearly  visible  when  thrown  on  the  screen. 
They  are  formed  by  rays  once  diffused  from  points  on  the  first  surface 
and  afterwards  regularly  reflected  and  refracted  from  the  froJit  and 
back  faces  of  the  two  plates  in  succession.  Professor  Adams  jjointed 
out  that  this  instrument  would  form  a  convenient  means  of  obtaining 
polarized  light  in  cases  where  the  length  of  a  Nicol's  prism  is  ob- 
jectionable, for  instance,  under  the  stage  of  a  Microscope  ;  the  light 
will  be  completely  polarized  if  the  plates  be  placed  to  receive  the 
light  at  the  polarizing  angle,  and  the  field  will  be  much  brighter  than 
when  a  plate  of  tourmaline  is  employed.* 

New  Anthozoa. — Professor  Studer,  of  Berne,  continues  in  the 
July-August  number  of  the  '  Monatsbericht '  of  the  Berlin  Academy 
the  description  of  the  forms  collected  during  the  voyage  of  the 
'  Gazelle '  round  the  world. 

The  new  species  (all  of  which  are  figured)  are  the  following : — 

Cereus  brevicornis. 
Calliactis  rnarmorata. 
Bunodes  Kenjuelensis. 
Bolocera  Kerguelensis. 


Madrepora  patella. 

,,         selago. 

,,         candelabrum. 

„  rubra. 

„         nana. 
Seriatopora  Jeschkei. 

„  cornpressa. 

„  contorta. 

Corynactis  carnea. 


Actinopsis  rosea. 
Paractis  alba. 
Halcampa  purpurea. 
Edwardsia  Kerguelensis. 


*  '  Nature,'  vol.  xix.  p.  6S. 


88  NOTES   AND    MEMORANDA. 

Forty-six  other  species  (not  new)  are  also  mentioned,  and  most 
of  them  described,  four  being  figured  (Madrepora  tuhulosa,  Ehrbg. ; 
M.formosa,  Dana ;  Seriatopora  oculata,  Ehrbg. ;  Epizoanthus  cancriso- 
cius,  V.  Mart.). 

The  last-mentioned  form  is  parasitic  on  the  outside  of  the  shell 
of  a  whelk,  the  interior  of  which  has  again  for  a  tenant  a  species  of 
hermit  crab.  It  is  thus  described  : — Upon  a  flat  bisal  membrane, 
which  covers  the  shell  of  Buccinum  porcatum,  Gmel.,  inhabited  by 
Eupagurus,  rise  the  Polypes,  which  are  5-10  mm.  high,  and  4-7 
mm.  in  diameter,  at  distances  varying  from  5-11  mm.  They  are 
^principally  on  the  dorsal  side  of  the  shell ;  the  ventral  side,  which 
touches  the  ground  by  the  motion  of  the  Pagurus,  having  none.  The 
whole  of  the  basal  membrane  is  penetrated  with  fine  angular  grains 
of  sand,  which  consist  for  the  greater  part  of  quartz  and  a  black 
hornblende.  The  spongy  coeneuchyma  comjiletely  absorbs  the  shell 
substance,  and  entirely  takes  its  place.  Even  the  spire  consists  of 
ccenenchyma  impregnated  with  sand,  excepting  a  small  remainder, 
which  is  represented  by  a  thin  film  of  cLalk.  The  tentacle  disk  of 
the  naked  polype  is  circular,  the  mouth  small,  and  with  two  lips ;  on 
the  circumference  of  the  disk  rise  two  circles  of  tentacles,  the  inner 
of  which  contains  the  largest  tentacles.  These  are  cylindrical,  short, 
and  not  attaining  the  length  of  the  circumference  of  the  disk.  Each 
circle  contains  twenty-four  tentacles.  The  continuation  of  the  body 
cavities  of  the  polypes  is  formed  by  a  fine  network  of  canals  which 
penetrate  through  the  layer  of  ccenenchyma.  From  the  bases  of 
each  polype  further  spread  twenty-four  canals  as  direct  continuations 
of  the  chambers ;  after  a  short  course,  they  lose  themselves  in  a 
network  of  anastomosing  canals,  leaving  only  small  spaces  between, 
which  are  filled  up  with  firm  masses  of  ccenenchyma ;  they  sjiread 
over  the  whole  basal  membrane.  The  colony  when  alive  was  rose 
red  in  colour.  Six  specimens  of  this  beautiful  form  were  taken  in  a 
drag  net  south  of  the  Cape  of  Good  Hope,  in  lat.  34°  13'  6"  S.,  and 
long.  15°  0'  7"  E.,  at  117  fathoms  depth.* 

Parthenogenesis  in  Bees. — According  to  a  theory  of  M.  Dzierzon 
developed  by  Professor  Siebold,  the  eggs  from  which  drone  bees  are 
produced,  are  deposited  without  fecundation  by  the  queen,  who  can 
'fecundate  them  or  leave  them  unfertilized,  according  as  they  are  in- 
tended to  produce  females  or  males.  M.  Perez  has  recently  discussed 
the  subject  in  a  note  to  the  French  Academy,|  in  which  he  says, "  Accord- 
ing to  a  classical  theory,  which  had  its  birth  in  Germany  and  which 
no  one  now-a-days  disputes,  a  fecundated  egg  of  the  queen  bee  is  a 
female  egg,  and  all  unfecundated  eggs  of  the  queen  bee  are  male. 
Tlie  mother  bee,  it  is  said,  can  even  lay  at  will  an  egg  of  one  or  the 
other  sex.  This  faculty,  which  is  exceptional  in  the  animal  king- 
dom, is  explained  by  assuming  that  the  bee,  at  the  moment  of  the 
passage  of  the  egg  iiito  the  oviduct,  can  ajiply  to  it  or  not  a  certain 
quantity  of  the  seminal  fluid  contained  in  the  seminal  recei)tacle. 
Nevertheless,  the  organization  of  the  generative  apparatus  of  tlie  bee 

*  '  Monatsbcriclit  d.  Kongl.  Preuss.  Akad.,'  1878,  July-Aug.,  p.  524. 
t  '  Coraptea  Kendus,'  vol.  Ixxxvii.  p.  408. 


NOTES    AND    MEMORANDA.  89 

does  not  differ  essentially  from  that  of  the  majority  of  female  insects, 
to  which  no  one  has  ever  thought  of  ascribing  the  power  of  acting  at 
pleasure  upon  phenomena  which  seem  to  be  absolutely  removed  from 
the  influence  of  the  will."  The  theory  was  founded,  at  least  in  part, 
upon  the  supposed  fact  that  an  Italian  queen,  fertilized  by  a  German 
drone,  would  produce  hybrid  workers  and  queens  (females)  and  drones 
exactly  like  herself.  M.  Perez,  however,  disputes  this  on  the  ground 
of  observations  made  upon  a  hive,  the  queen  of  which,  the  daughter 
of  an  Italian  of  pure  race,  had  been  fertilized  by  a  French  drone. 

Some  of  the  workers  were  Italian,  others  French,  others  mixed  in 
various  proportions  of  the  two  races.  Among  the  males  also  were 
some  as  dark  as  those  of  the  French  race,  although,  according  to  the 
above  theory,  they  ought  all  to  have  been  of  the  Italian  race,  like 
their  mother.  He  therefore  examined  300  of  the  drones,  and  found 
151  were  pure  Italian,  60  were  hybrids  of  various  degrees,  and  83  were 
French. 

Hence  he  regards  it  as  evident  that  the  drone  eggs,  like  those  of 
the  females,  are  fertilized  by  contact  with  the  fluid  stored  up  in  the 
seminal  receptacle  of  the  queen,  and  that  Dzierzon's  theory  must  fall 
to  the  ground. 

On  this  paper  M.  A.  Sanson  in  a  later  number  *  comments  as 
follows : — 

In  a  recent  note  M.  J.  Perez  is  inclined  to  throw  doubt  on  the 
phenomenon  of  parthenogenesis  amongst  bees,  taking  his  stand  on  a 
certain  interpretation  of  facts  of  heredity  which  he  has  observed.  I 
have  reason  to  be  surprised  at  seeing  him  qualify  as  an  hypothesis  a 
fact,  experimentally  proved  a  great  many  times,  and  of  which  the 
direct  verification  is  most  easy.  A  proof  of  this  fact  was  submitted 
to  the  Academy  in  1868. f  I  presented  a  comb  containing  only  cells 
of  workers  filled  with  males  or  drones  developed  in  these  cells. 
M.  Bastian  and  I  obtained  it  at  Wissembourg,  by  making  a  queen 
bee  lay  in  it,  whose  seminal  receptacle  was  destitute  of  spermatozoids. 
I  presented  also,  at  the  same  time,  some  workers  lodged  in  male  cells, 
and  hatched  from  eggs  laid  by  a  fecundated  queen  bee  who  had  no  other 
cells  at  her  disposal.  The  object  of  our  experiments  was  to  examine 
into  the  theory  advanced  at  that  time  by  Laudois  relating  to  the 
mode  of  development  of  the  sexes.  All  bee-keepers  know  that  the 
old  queens,  who  become  drone-mothers,  that  is,  who  no  longer  lay  any 
but  male  eggs,  have  exhausted  their  provision  of  spermatozoids. 
.  When  their  seminal  receptacle  is  examined  under  the  Microscope,  it 
contains  nothing  but  a  perfectly  transparent  liquid.  It  is  also  known 
that  the  temperature  of  a  young  fecundated  queen  has  only  to  be 
lowered  to  the  degree  which  kills  spermatozoa,  to  render  her  imme- 
diately a  drone-mother.  The  young  queens  who  have  not  paired, 
and  the  workers  who  sometimes  lay  in  hives  which  have  lost  their 
queen  by  accident,  and  which  are  called  "  orphans,"  only  lay  male 
eggs. 

These  are  the  facts.     It  is  easy  to  show,  moreover,  that  the  inter- 

*  '  Comptes  Rendus,'  vol.  Ixxxvii  p.  G59. 
t  Vol.  Ixxvii.  p.  51. 


90  NOTES    AND    MEMORANDA. 

pretatiou  given  by  M.  J.  Perez  of  his  observations  is  not  what  it 
ought  to  be.  In  a  hive  of  which  the  queen  was,  he  says,  the  daughter 
of  an  Italian  of  pure  race  and  had  been  fecundated  by  a  French  male, 
he  examined  with  scrupulous  care  300  males.  He  found  Italian 
characters  in  161 ;  hybrid  characters  in  varying  degree  in  66,  and 
French  characters  in  83.  From  which  it  follows  evidently,  he  adds, 
that  the  eggs  of  drones,  like  the  eggs  of  females,  receive  the  contact 
of  the  semen  deposited  by  the  male  in  the  organs  of  the  queen,  and 
that  the  theory  of  Dzierzon,  which  was  created  to  explain  an  ill- 
proved  fact,  becomes  useless  if  this  fact  is  disproved. 

We  are  not  at  all  struck  by  the  evidence  of  such  a  conclusion, 
being  in  a  position  to  interpose  the  known  laws  of  heredity.  With 
an  Italian  queen  of  incontestably  pure  race,  the  drones  have  ex- 
clusively Italian  characters,  although  she  may  have  j)aired  with  a 
male  of  another  race.  The  workers  alone  are  hybrids.  The  author 
has  evidently  had  before  him  a  case  of  reversion.  In  his  hive  there 
was,  according  to  what  he  informs  us,  some  true  Italian  workers, 
others  which  were  French,  others  presenting  a  mixture,  in  different 
proportions,  of  the  characters  of  the  two  races.  This  is  conformable 
to  the  usual  results  of  crossing.  The  queen  of  this  hive  was  doubtless 
an  Italian  of  the  same  kind  as  that  of  the  workers  of  the  first 
category.  The  atavism  of  a  black  male  who  had  intervened  in  a 
preceding  generation  was  manifested  in  different  degrees.  The  same 
fact  is  often  shown  in  the  hives  of  Germany  or  of  France  in  which 
Italian  queens  have  been  introduced.  I  remember  having  myself 
made  a  similar  observation  in  that  of  M.  Bastian,  at  Wissembourg,  by 
proving  the  hybrid  origin  of  the  queen  whose  external  characters 
were  otherwise  purely  Italian. 

In  any  case,  the  parthenogenesis  of  bees  cannot  be  considered  as  an 
hypothesis  admissible  only  by  reason  of  its  utility  to  explain  a  fact 
otherwise  incontestable,  since  its  reality  was  established  by  experi- 
ment long  ago. 

New  Classification  of  the  Vegetable  Kingdom. — Professor  Caruel, 
of  Pisa,  proposes  the  following  classification  : — (1)  Phanerogam ia  {in 
the  subdivisions  discarding  the  distinction  between  Gymnospermia 
and  Angiospermia,  retaining  as  the  two  primary  classes  Monocoty- 
ledons and  Dicotyledons,  and  giving  the  higher  rank  to  the  former). 
(2)  Schistogamia  (including  Characece  only).  (3)  Prothallogamia 
(vascular  Cryptogams  divided  into  HeterosporcB  and  Isosporoi).  (4) 
Bryogamia  (synonymous  with  Miiscinece,  and  divided  into  Miisci  and 
HepaticcB).  (5)  Gymnogamia  (Thallophyta  or  cellular  Cryptogams), 
The  simplest  Gymnogamia  possesses  only  a  single  form,  which  is 
reproduced  organically  by  fission,  by  conidia  and  sporidia,  or  by 
gamogenesis,  but  without  any  sexual  differentiation.  In  others  there 
is  sexual  differentiation  into  male  and  female  forms ;  a  few  have  also 
a  third  neutral  form,  when  the  oospore  produces  zoospores  instead  of 
passing  directly  into  the  female  form.  They  resemble  the  Bryogamia 
in  the  definite  development  of  the  neutral  form  and  the  indefinite 
development  of  the  female  form,  but  differ  in  the  zoospore-like  form 
of  the  phytozoa,  and  in  the  structure  of  the  oogonium,  which  is  iso- 


NOTES    AND    MEMORANDA,  91 

lated  and  naked,  and  does  not  form  parts  of  an  archegonium.  Pro- 
fessor Caruel  altogether  discards  the  old  classification  of  Thallophytes 
into  AlgBB,  Fungi,  and  Lichens,  but  does  not  propose  any  other  in  its 
place,  and  thinks  it  probable  that  as  our  knowledge  of  some  of  its 
forms  increases,  it  will  be  broken  up  into  several  primary  groups. 
He  considers  it  would  be  an  advantage  if  the  term  Cryptogamia  were 
altogether  discarded.* 

The  Morphology  of  the  Oxytrichina.  —  Some  important  obser- 
vations have  been  made  by  Professor  V.  Sterki  on  this  subject,f  which 
may  be  shortly  summed  up  as  follows  : — ■ 

1.  Form  and  Size. — The  Oxytrichina  and  indeed  the  whole  group 
of  Hypotricha  are  usually  described  as  having  a  convex  dorsal  and  a 
flat  ventral  side.  This  is  not  imiversally  true :  0.  gihha  {Amphisia 
(jibha,  Sterki)  has  the  ventral  side  concave  with  prominent  edges, 
while  other  forms  are  equally  convex  on  both  surfaces  ;  one  is  rounded 
and  spindle-shaped,  and  another  has  a  flat  dorsal  side.  Distinct 
varieties  of  some  species  have  been  observed,  as  well  as  undoubted 
monstrosities. 

2.  Body-substance — Consistency. — Muscle-strite  (Myophanstreifen) 
occur  in  some  cases.  In  Stylonichia  mytilus  suffering  from  want  of 
water,  all  the  protoplasm  was  seen  to  form  a  network  enclosing  com- 
municating vacuoles  in  which  was  contained  a  watery  fluid  or 
"  serum."  Probably  the  contractile  vesicle  is  a  modified  vacuole. 
There  is  an  unbroken  chain  of  transition  forms  between  species  with 
a  carapace  and  those  possessing  the  greatest  amount  of  "  Meta- 
bolicitat  "  or  power  of  changing  their  form. 

3.  Peristome. — The  structui'e  in  the  oesophagus  of  Stylonichia, 
described  as  the  mouth-cleft  by  Stein,  and  as  a  second  undulating 
membrane  by  Engelmann,  is  really  a  row  of  long,  delicate,  undulating 
cilia ;  the  author  calls  these  the  endoral  row.  He  also  describes  a  row 
of  paroral  cilia,  inserted  along  the  line  of  attachment  of  the  adoral 
row,  and  directed  inwards. 

4.  Ciliation. — Those  cilia  which  are  disposed  in  rows  are  usually 
fewer  in  number  and  of  greater  size  than  they  are  usually  rej^resented. 
Thus  Sterki  counts  forty  to  fifty  large  cilia  in  the  adoral  row  of  Stylo- 
nichia mytilus,  as  against  the  200  fine  ones  of  Stein.  There  is  no  absolute 
distinction  in  nature  between  styles  and  bristle-like  cilia ;  moreover, 
in  one  and  the  same  species  intermediate  forms  are  met  with  between 
the  finest  cilia  and  the  strongest  "  styles."  The  marginal  and  anal 
cilia  are  of  a  flattened  form ;  the  large  frontal  and  ventral  cilia  of 
Stylonichia  and  Oxytricha  are  often  polygonal  in  section ;  in  S.  mytilus 
some  of  the  frontal  cilia  are  semicircular  in  section.  The  flattenino' 
of  cilia  is  most  marked  in  the  adoral  set,  which  are  so  modified  as 
to  form  fan-like  plates,  called  by  the  author  membranelles  CMem- 
branellen) ;  he  finds  them  in  all  Oxytrichce  as  well  as  in  Euplotce  and 
AmphidisccB,  in  the  peritrichous  Halteria  and  in  Stentor.  When  in 
action,  the  opposite  edges  of  the  row  of  membranelles  give  the 
appearance  of  a  double  row  of  cilia.     In  the  matter  of  the  location  of 

*  Mr.  A.  W.  Bennett,  in  '  American  Naturalist,'  vol.  xii.  p.  747. 
t  '  Zcitseh.  f.  wiss.  Zool.,'  vol.  xxx. 


92  NOTES   AND    MEMORANDA. 

cilia  tbero  are  two  distinct  groups  of  Oxi/trlchina,  or  rather  two  extreme 
modifications  with  intermediate  forms.  In  one  of  these,  including 
Oxytrlcha,  StylonicMa,  &c.,  the  cilia  are  greatly  differentiated  both  as 
to  form  and  function,  and  limited  in  number :  in  the  other  (  Uroleptus, 
IJrostyla)  there  are  two  rows  and  upwards  on  ventral  cilia,  each  row 
containing  an  indefinite  number.  A  new  genus  and  species,  Tricho- 
gaster  pilosus,  is  interesting  from  the  fact  that  it  is  the  lowest  known 
form  of  Oxytrichina,  its  cilia  presenting  the  smallest  amount  of 
differentiation. 

For  the  sake  of  clearness,  the  author  proposes  to  distinguish  by 
numbers  the  eight  characteristic  frontal  cilia  of  StylonicMa,  Oxytricha, 
Histrio  (nov.  gen.),  PleurutricJia,  and  AUotricha  (nov.  gen.).  The 
dorsal  cilia  are  not,  as  Stein  thought,  young  marginal  cilia.  They 
occur  over  the  whole  dorsal  surface  in  longitudinal  rows,  each  row 
being  set  in  a  distinct  furrow.  They  exhibit  little  movement,  and 
are  differently  constructed  to  the  other  cilia,  being  mere  cuticular 
processes,  containing  but  little  protoplasm.     They  may  be  absent. 

5.  Transverse  Division. — A  very  exact  account  is  given  of  the 
development  of  the  new  cilia  of  the  two  daughter-individuals  arising 
by  a  process  of  transverse  division.  According  to  Stein,  the  new 
marginal  cilia  arise  as  a  single  longitudinal  row  on  each  side,  which 
subsequently  divides :  but  according  to  Sterki  this  account  is  incorrect. 
He  states,  in  fact,  that  the  mode  of  origin  of  the  marginal  cilia  is 
different  on  the  right  and  left  sides,  and  takes  place  as  follows  : — On 
the  right  side  the  row  of  marginal  cilia  of  the  parent  splits  up  into 
three  groups,  enclosing  two  intervals,  in  each  of  which  appear  fine 
close-set  cilia.  These  arise  somewhat  nearer  the  margin  than  the 
old  cilia,  and,  as  development  goes  on,  they  get  further  and  further 
from  one  another,  the  rows  themselves,  at  the  same  time,  approaching. 
The  old  cilia  simultaneously  undergo  absorption,  although  young  in- 
dividuals are  often  met  with  which  have  some  of  the  maternal  cilia 
left.  On  the  left  side  the  parental  marginal  cilia  split  up  into  only 
two  groups  :  in  the  single  interval  between  them  appears  one  of  the 
new  rows,  the  second  making  its  appearance  between  the  anterior  end 
of  the  old  row  and  the  adoral  cilia.  A  further  difference  between 
the  two  sides  is  met  with  in  the  fact  that  the  new  marginal  cilia  of 
the  left  side  arise  further  from  the  margin  than  the  old  ones. 

In  StylonicMa,  Oxytricha,  and  Histrio,  the  frontal,  ventral,  and 
anal  cilia  of  each  daughter-cell  arise  from  a  common  group  of  eighteen 
cilia,  that  of  the  anterior  individual  being  situated  to  the  right  of  the 
parent  peristome,  that  of  the  posterior  individual  to  the  right  of  the 
new  peristome.  Each  group  consists  of  six  oblique  rows,  containing 
1,  3,  3,  3,  4,  4,  cilia  respectively,  counting  from  left  to  right.  Of  these 
the  single  cilium  of  the  first  (leftmost)  row,  the  two  anterior  cilia  of  the 
second  and  third  rows,  and  the  three  anterior  of  the  sixth,  become  the 
eight  frontal  cilia ;  the  two  anterior  cilia  of  the  fourth,  and  the  three 
anterior  of  the  fifth  row,  become  the  five  ventral  cilia  ;  while  the 
posterior  cilium  of  each  row  except  the  first  becomes  one  of  the  five 
anal  cilia. 

During  division,  the  anterior  or  old  peristome  alters  its  form. 


NOTES   AND    MEMORANDA.  93 

becoming  slender  and  flattened  like  the  new  or  posterior  peristome. 
Afterwards,  both  peristomes  increase  in  length  and  breadth,  so  that  at 
the  end  of  the  process  they  are  both  in  the  saiae  stage.  The  new 
caudal  cilia  always  arise,  as  Stein  made  out  in  Stijlonichia,  on  the 
dorsal  side :  the  prfeoral  cilia  and  undulating  membrane  are  formed 
anew,  the  old  ones  being  absorbed.  The  adoral  cilia  or  membranelles 
are  probably  directly  transformed,  like  the  peristome,  into  those  of  the 
new  individual.  The  new  cilia  all  exhibit  a  sort  of  clumsiness  of 
movement,  quite  different  to  the  facility  of  their  adult  motions. 

The  author  remarks  that  the  process  of  division  in  Oxytrichina  is 
not  one  of  true  fission,  but  is  rather  one  of  bud-formation. 

In  an  appendix  Sterki  gives  the  characters  of  some  new  genera  and 
species  he  has  established.  The  new  genera  are  Histrio  (  =  Stylonichia 
hisfrio),  Amphisia,  and  Gonosfomum  (separated  from  Oxytricha),  Stylo- 
nethes,  Allotricha,  Strongylidium,  and  Trichocj aster. 

The  Sexual  Process  in  Diatoms. — An  article  on  this  question,  con- 
taining a  discussion  on  the  sexual  process  in  general,  occurs  in  '  Der 
Naturforscher '  for  November  23,  1878.  The  writer  begins  by  a 
statement  of  the  five  methods  in  which  the  auxospores  of  Diatomacete 
are  known  to  be  formed  :  these  are  the  following  :  — 

1.  A  single  individual  throws  off  both  valves,  secretes  a  mucila- 
ginous investment,  extends  itself,  and  grows.  The  auxospore  tlius 
formed  surrounds  itself  with  a  thin  membrane  devoid  of  silica,  and 
within  this  secretes  the  usual  pair  of  siliceous  valves,  thus  forming  the 
"firstling-cell"  (Erstlingzelle)  of  a  new  generation. 

2.  The  protoplasm  of  a  cell  divides  into  two  naked  daughter-cells, 
which  make  their  way  out  of  the  mother-cell,  and  form  an  auxospore. 

3.  Two  individuals,  lying  close  to  one  another,  secrete  an  invest- 
ment of  mucilage :  both  these  throw  off  their  valves,  and  so  form  a 
pair  of  naked  cells  lying  in  close  proximity  to  one  another,  but 
without  actually  touching.  Both  of  these  extend  parallel  to  one 
another  in  the  direction  of  their  length  until  they  attain  the  normal 
size  of  auxospores ;  outside  these  a  thin  membrane  (perizonium)  is 
found,  and  within  this  the  ordinary  siliceous  valves. 

4.  Two  individuals,  generally  surrounded  by  a  gelatinous  invest- 
ment, throw  off  their  old  valves,  and  coalesce  into  a  single  naked  mass 
of  protoplasm,  which  grows  into  a  single  auxospore. 

5.  Two  individuals,  again  surrounded  by  mucilage,  throw  off  their 
old  valves,  and  each  divides  transversely  into  two  naked  daughter- 
cells,  each  of  which  then  coalesces  with  the  corresponding  daughter- 
cell  of  the  other  individual.  Two  naked  zygospores  are  thus  formed, 
each  of  which  becomes  an  auxospore,  and  subsequently,  by  the  forma- 
tion of  siliceous  valves,  a  firstling-cell. 

Of  these  five  methods  the  fourth  and  fifth  are  certainly  sexual, 
being  a  process  of  zygospore-formation.  The  fii'st  mode  is  as  certainly 
asexual,  a  process  of  cell-formation  by  rejuvenescence,  so  tLat  in  the 
single  group  of  Diatomacece.  the  auxospores,  by  which  a  new  generation 
is  started,  may  be  produced  either  sexually  or  asexually. 

The  second  mode  requires  further  investigation  :  about  the  third 
there  is  a  diflSculty ;  it  is  a  pi'ocess  of  rejuvenescence,  taking  place, 


94  NOTES   AND    MEMOBANDA. 

however,  only  wlien  two  individuals  are  present ;  so  tliat  a  mutual 
action,  independent  of  actual  contact,  is  evidently  exerted.  This  pro- 
cess the  writer  compares  to  the  mode  of  fertilization  in  Floridece,,  where 
cells  far  removed  from  the  trichogyne,  to  which  alone  the  fertilizing 
influence  of  the  spermatia  is  ajiplied,  are  stimulated  to  a  new  and 
vigorous  growth  by  the  impregnation ;  and  to  the  process  which 
obtains  in  Phanerogams,  where  the  protoplasms  of  the  male  and  female 
cells  arc  sejiarated  from  one  another  by  the  cell- wall  of  the  pollen 
tube.  In  both  these  cases,  however,  one  of  the  sexual  cells  only  (the 
female  cell)  undergoes  further  growth,  the  other  or  male  cell  disap- 
pearing ;  while  in  the  desmids  in  question,  the  action  of  the  two  cells 
is  mutual. 

The  writer  then  defines  sexuality  as  the  action  of  two  or  more  cells 
on  one  another,  by  means  of  which  a  new  process  of  growth,  in  one  or 
all  of  these  cells,  is  set  up,  and  the  sexual  action  consists  in  the  stimu- 
lation of  the  sexual  cells  to  a  new  and  peculiar  growth,  such  growth 
being  impossible  without  that  stimulation. 

Microscopical  Injection  of  Molluscs. — Dr.  W.  Flemming  has 
originated  *  a  method  of  killing  molluscs  for  purposes  of  fine  injection, 
which  he  has  found  very  successful.  He  recommends  freezing  the 
animal  by  means  of  a  mixture  of  ice  and  salt,  and  placing  it,  when 
frozen,  in  tepid  water  for  a  quarter  of  an  hour  ;  it  is  then  found  to  be 
dead  and  stiif  with  the  valves  gajiing,  and  the  muscles  no  longer  offer  any 
opposition  to  the  passage  of  the  injection.  Unlike  many  other  methods 
of  killing,  this  freezing  process  produces  no  injury  to  the  tissues. 

In  injecting  Lamellibranchs  from  the  heart,  there  is  great  danger 
of  extravasation.  To  obviate  this  difficulty,  Flemming  recommends 
wiping  the  surface  carefully  after  insertion  of  the  cannula,  and  then 
covering  the  animal  with  a  soft  paste  of  plaster  of  Paris.  If  this  is 
done  successfully,  the  cannula  is  firmly  fixed  in  its  place,  and  extrava- 
sation from  the  cut  surfaces  of  the  adductors  and  other  dangerous 
places  is  effectually  prevented. 

Parasitism  amongst  Infusoria.— Dr.  J.  van  Eeesf  has  observed 
three  cases  of  parasitism  in  this  group,  two  of  which  are  new,  while 
in  the  case  of  the  third  his  account  differs  somewhat  from  that  of  its 
discoverer. 

1.  Vorticella  microstoma. — The  curious  parasite  Endosplicera  having 
this  sj)ecies  for  its  host,  was  first  described  by  Engelmann  in  the  first 
volume  of  the  '  Morphologisches  Jahrbuch.'  Endosplicera  is  a  peri- 
trichous  infusor  found  in  the  interior  of  the  body  of  Vorticella,  where 
it  multiplies  by  budding,  the  buds  making  their  way  out  of  the  body 
of  their  host  and  swimming  freely  in  the  water  for  a  longer  or  shorter 
time,  imtil  another  Vorticella  is  met  with.  Engelmann  stated  that 
the  parasite  is  then  taken  into  the  body  of  its  Lost  by  the  ciliary 
current  of  the  latter,  but,  according  to  Eees,  it  fixes  itself  about  half- 
way between  the  proximal  and  distal  ends  of  the  Vorticella's  body, 
into  which  it  gradually  penetrates,  still  showing  its  nucleus  and  con- 

*  '  Archiv  f.  Mik.  Auat.,'  vol.  xv.  p.  252. 
t  '  Zeitsch.  f.  wiss.  Zool.,'  vol.  xxxi.  p.  473. 


NOTES   AND    MEMORANDA.  95 

tractile  vesicle.  Engelmaun  found  that  a  posterior  circlet  of  cilia 
was  developed  in  the  infected  Vorticclla,  which  then  swam  away,  but 
in  the  cases  observed  by  Eees,  the  Vorticclla  drew  itself  together  and 
sometimes  became  encysted.  In  one  case  quite  an  Endosphcera  epidemic 
was  observed. 

2.  Vorticella  campamda.  —  Amongst  normal  individuals  some 
specimens  Avere  seen  containing  large,  strongly  refracting  spheres, 
exhibiting  a  single  contour,  granular  contents,  and  a  dark,  strongly 
refracting,  spherical  or  oval  nucleus ;  no  contractile  vesicle  was  ob- 
served. Each  Vorticella  contained  from  two  to  eight  of  the  spheres, 
the  size  of  which  was  inversely  pi'oportional  to  their  number,  but 
usually  constant  for  each  infected  specimen.  In  one  case,  however, 
one  sphere  was  decidedly  larger  than  any  of  the  other  in  the  same 
specimen,  and  had  two  nuclei,  whence  it  is  inferred  that  multiplication 
takes  place  by  division  within  the  body  of  the  host.  The  further  fate 
both  of  host  and  parasite  is  unknown,  and  no  opinion  is  advanced  as 
to  the  nature  of  the  latter. 

3.  Oxylricha  faUax. — The  appearance  presented  by  the  infected 
individuals  in  this  case,  seemed,  at  first  sight,  to  lend  great  support  to 
the  theory  that  the  nucleus  is  a  germ-producing  organ.  The  parasite, 
to  which,  as  in  the  preceding  case,  the  author  gives  no  name,  occurs 
within  the  nucleus  of  Oxijtriclia,  in  the  form,  at  first,  of  minute 
spheres,  which  are,  except  in  the  case  of  the  smallest  of  all,  nucleated, 
but  are  devoid  of  a  contractile  vesicle.  In  further  stages  the  spheres 
increased  greatly  in  size,  and  exhibited  a  distinct  cell-wall,  and  under- 
went multiplication  by  fission.  In  the  latter  process  the  cell-wall 
took  no  part,  and  the  division  masses  did  not  at  first  round  themselves 
ofi'.  The  nucleus  of  the  Oxijtriclia  became,  of  course,  greatly  altered 
in  shape,  and  in  the  final  stages  usually  disappeared.  The  spheres 
either  escaped  through  an  aperture  in  the  substance  of  their  host,  or 
were  liberated  by  its  disintegration.  In  either  case,  the  daughter- cells 
of  spheres  which  had  undergone  division,  rounded  themselves  oif,  after 
being  liberated,  and  exhibited  slow  movements,  due,  the  aiithor  thinks, 
to  very  minute  cilia,  which  he  believes  he  was  able  to  see  in  some 
instances.  After  a  time  the  movements  ceased,  and  the  daughter-cells 
were  gradually  transformed  into  a  granular  mass,  devoid  of  any  trace  of 
cell-contours.  The  author  seems  to  think  it  probable  that  the  cell- 
colonies  thus  formed  divide  into  single  cells,  and  that  these  latter,  or 
the  products  of  their  division,  finally  penetrate  into  the  body  of 
Oxytricha  fallax.    He  believes  the  parasite  to  be  one  of  the  lower  Algce. 

Microscopy  at  the  American  Association  for  the  Advance- 
ment of  Science. — At  the  meeting  of  this  Association,  to  be  held  in 
August,  1879,  Professor  E.  W.  Morley,  of  Hudson,  Ohio,  will  be  the 
Chairman  of  the  sub-section  of  Microscopy. 

Germination  of  the  Spores  of  Volvox  dioicns. — Although  the 

'  Journal  de  Micrographie  '  says  that  '  All  microscopists  are  acquainted 

with  the  work  of  Cohn  on  Volcox  glohator,'  *  we  believe  we  are  correct 

in  saying  that  very  little  was  known  of  it  in  this  country  until  t]]e 

*  'Beitrilge  ziir  Biologie  tier  Pfliaizen,'  vol.  i.  pait3,  1875. 


96  NOTES    AND    MEMORANDA. 

publication  of  Mr.  A.  W.  Bennett's  valuable  summary  of  Cobu's  views 
last  year.*  M.  F.  Henneguy,  of  tbe  College  of  France,  two  years  ago 
communicated  to  tbe  Academy  of  Sciences  a  note  as  to  tbe  reproduc- 
tion of  Volcox  dioicus  (Cobn),  in  wbich  be  pointed  out  tbe  gradual 
appearance  of  sexuality  in  tbese  organisms,  the  male  sex  appearing 
before  tbe  female  in  proportion  as  tbe  species  degenerates  by  sexual 
reproduction.  He  bas  now  added  further  observations,  of  which  the 
following  are  the  more  important  results.f 

The  spores  arising  from  the  fecundation  of  the  oospheres  by  tbe 
antherozoids  fall  to  tbe  bottom  of  the  water  and  remain  in  a  stationary 
state  for  a  long  time.  Cobn  thought  that  these  spores  must  be  dried 
before  germinating,  though  be  did  not  observe  tbe  germination. 
Cienkowski  saw  the  contents  of  the  spore  divide,  and  be  thought  that 
each  sphere  of  segmentation  became  ultimately  a  ccEnobium. 

M.  Henneguy  has  ascertained  that,  contrary  to  Cohn's  opinion,  the 
spores  of  Volvox  pass  tbe  winter  in  the  water.  Those  observed  were 
collected  in  tbe  miid  of  a  basin  of  tbo  Jardiu  des  Plantes,  deep  and 
constantly  filled  with  water. 

These  spores,  of  an  orange-yellow,  possess  two  enveloping  mem- 
branes— an  exospore  with  double  outline,  and  a  very  thin  endospore. 
At  the  moment  of  germination,  tbe  exospore  is  torn  open,  and  the 
swollen  endospore  is  seen  to  project  through  tbe  openings.  At  tbe 
same  time  tbe  contents  of  the  spore,  separated  from  tbe  endospore  by 
a  clear  space,  divide  into  two  equal  parts,  which,  by  successive 
bipartitions,  give  birth  to  four,  eight,  sixteen,  &c.,  small  cells.  Tbe 
cells,  at  first  orange-yellow,  acquire  a  brown  tint,  becoming  more  and 
more  greenish  in  proportion  as  the  work  of  division  advances.  When 
tbe  segmentation  of  the  spore  bas  terminated,  tbe  cells  form  a 
spherical  layer  analogous  to  tbe  blastoderm  of  a  boloblastic  ovum. 
Each  element  then  acquires  two  vibratile  cilia.  The  endospore  dis- 
appears and  the  young  Volvox,  thus  constituted,  moves  freely  in  tbe 
water.  Tbe  cells,  at  first  very  close  together,  separate  one  from 
another  by  the  interposition  of  a  gelatinous  matter. 

A  fact  interesting  to  note  is  the  presence  among  the  vegetative 
cells  of  the  Volvox  still  contained  in  the  endospore,  of  elements  larger 
than  tbe  others,  wbich  will  subsequently  give  origin  to  the  daughter 
colonies  by  a  mode  of  division  analogous  to  that  observed  in  tbe  spore. 

Tbe  spores  of  Volvox  therefore  germinate  in  water,  and  each  of 
tbem  produces  a  single  colony  by  a  jn-ocess  of  segmentation  identical 
with  that  which  gives  rise  to  a  daughter  colony  at  tbe  expense  of  a 
cell  of  tbe  mother  colony. 

Parasitism  of  a  Coral  on  a  Sponge.— Tbe  discussion  at  tbe 
January  meeting  on  this  subject  will  be  found  in  tbe  '  Proceedings ' 
at  p.  110. 

*  See  '  Pop.  Sc.  Keview,'  N.  S.,  vol.  ii.  p.  225. 

t  'Journal  de  Micrographie,'  vol.  ii.  p.  485.     'Bull.  Soc.  Philomath. ,' Paris, 
July,  1878. 


(     ^7     J 


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JOURNALS,  TRANSACTIONS,  &c.  :— 
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*  The  contents  of  Microscopical  Journals  are  given  in  full;  in  other  cases 
such  of  the  contents  as  relate  to  Biological  subjects  (principally  Invertebrata  and 
Cryptogauiia),  or  are  otherwise  interesting  to  Microscopists. 

VOL.    II.  H 


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CoMPTES  Eendtjs  Hebclomadaires  cles  Seances  de  I'Academie  des 
Sciences,*  Vol.  LXXXVII.,  No.  17  (21st  October)  :— 

On  the  Nerve  Terminations  in  the  Striated  Muscles.     By  M.  S.  Tscliiriew. 
On  the  Hydrophorous  Reservoirs  of  Dipsacus.     By  M.  A.  Barthe'lemy. 
Tlie  Influence  of  Salicylic  and  Thymic  Acid  and  some  Essences  on  Germina- 
tion.    By  M.  Ed.  Haeckel. 

No.  18  (28tb  October)  :— 

On  Parthenogenesis  in  Bees.     By  M.  A.  Sanson. 

No.  19  (4tb  November)  : — 

On  the  Region  of  the  Solar  Spectrum  indispensable  to  Vegetalile  Life.  By 
M.  P.  Bert. 

On  Relations  presented  by  Phenomena  of  Motion  proper  to  the  Reproductive 
Organs  of  some  Phanerogams  with  Cross  and  Direct  Fecundation.  By  M.  Ed. 
Haeckel. 

No.  20  (lltb  November)  :— 

The  Measurement  of  the  Magnifying  Power  in  Optical  Instruments.  By 
M.  G.  Govi. 

On  some  Causes  of  Inversion  of  Cane  Sugar,  and  on  the  consecutive  alterations 
of  the  Glucoses  formed.    By  M.  Durin. 


*  These  will  be  hereafter  referred  to  as  '  Comptes  Rendus — French  Academy.' 


BIBLIOGRAPHY.  101 

On  the  Oviposition  of  Bees.     By  M.  M.  Girard. 

The  presence  of  Alcoholic  Ferment  in  Air.     By  M.  P.  Miguel. 

Organization  of  Hygrocrocis  arscnicus,  Breb.     By  M.  L.  Marchand. 

No.  21  (18th  November)  :— 

Migration  of  Pucerons  of  Galls  of  Leutiscua  to  the  Roots  of  Gramineas,  By 
M.  J.  Lichtenstein. 

Disease  of  Lettuce  (Peronospora  ganjliiformis,  Berk.).    By  M.  Max  Cornu. 

No.  22  (25th  November)  :— 

Critical  Examination  of  a  posthumous  MS.  of  Claude  Bernard  on  Alcoholic 
Fermentation.     By  M.  L.  Pasteur. 

No.  24  (9th  December)  :— 

Diseases  of  Plants  caused  by  Peronospora :  attempted  treatment.     Application 
to  the  Lettuce  Disease  (P.  gaw/liifonnis,  Berk.).     By  M.  Max  Cornu. 
On  a  Disease  of  the  Cotfee  Tree  observed  in  Brazil.     By  M.  C.  Jobert. 
On  the  Difl"u=iou  of  Heat  by  Leaves.    By  M.  Maijnenne. 

No.  25  (16th  December):— 

Observations  on  the  Note  of  M.  Pasteur  relative  to  Alcoholic  Fermentation. 
By  M.  Berthelot. 

On  Hajmocyanine,  a  new  Substance  from  the  Blood  of  the  Poulp  (^Oot'pus 
vulgaris).     By  M.  L.  Fredericq. 

On  the  Influence  of  the  diiferent  Colours  of  the  Spectrum  on  the  Development 
of  Animals.     By  M.  E.  Yung. 

No.  26  (23rd  December)  :— 

Formation  of  Leaves  and  order  of  ai^pearance  of  their  first  vessels  in  the 
Gramiuese.     By  M.  A.  Tre'cul. 

On  the  Chromatic  Function  in  the  Poulp.     By  M.  L.  Fredericq. 

On  the  Excretory  Apparatus  of  Solenophorus  meijalocephalus.  By  M.  J. 
Poirier. 

New  Investigations  on  the  suspension  of  the  Phenomena  of  Life  in  the  Embryo 
of  the  Hen.     By  M.  Dareste.  , 

No.  27  (30th  December)  ;— 
Reply  to  M.  Berthelot.     By  M.  Pasteur. 

Observations  of  M.  Tre'cul  on  M.  Pasteur's  communicatiun,  and  reply  uf  M. 
Pasteur. 

Poison  of  Serpents.     By  M.  Lacerda. 

On  the  Function  of  Chlorophyll  in  green  Planarlte.     By  M.  P.  Geddes, 

Observations  of  M.  de  Quatrefages  relative  to  the  preceding  communication. 


Belgium. 
Bulletin  de  la  Societe  Belge  de  Mickoscopie,  Vol.  V.,  No.  2 : 

Proceedings  of  the  Meeting  of  28th  November,  containing : — 

Remarks  of  M.  Renard  on  the  Results  of  the  Microscopic  Study  of  Thin  Plates 
of  Fulgarite,  and  of  some  Products  of  Fusion  of  Quartzose  Substances. 

Remarks  of  M.  Ledeganck  and  M.  Coppez  on  Follicular  Conjunctiva.   (1  plate.) 

Notes  on  some  Diatoms.  By  F.  Kitton,  F.R.M.S.,  Corresponding  Member  of 
the  Society.     Translated  by  M.  J.  Deby.     (2  woodcuts.) 

Analytical  and  Critical  Review  of  various  articles  on  Fungi  and  other  Crypto- 
gamia,  by  M.  Max  Cornu  ;  of  the  '  Revue  des  Sciences  Naturelles  de  Montpellier '  ; 
of  an  article  by  M.  E.  IMallard  on  Bravaisite,  a  new  mineral  substance,  in  the 
'Bulletin  de  la  Socie'te'  Mineralogique  de  France,'  1878,  No.  1 ;  and  of  an  article 
by  M.  J.  Thoulet  in  No.  2  of  the  same  'Bulletin,'  on  the  Variations  of  the 
Angles,  and  Planes  of  Cleavage  on  the  Faces  of  the  princiiml  Zones  in  Pyroxene 
Amphibole,  Orthoae,  and  Triclinic  Felspars. 


102  BIBLIOGRAPHY. 

Germany. 

Aechiv  fur  Mikroskopische  Anatomie,  Vol.  XV,,  Part  4  (issued 
30th  October,  1878):— 

On  the  Mid-Gut  of  Cobitis  fossilis,  Lin.     By  Dr.  H.  Lorent.    (1  plate.) 

Contributions  to  the  Comparative  Morphology  of  the  Skeletal  System  of 
Vertebrata.  By  Dr.  A.  Goette,  Professor  at  Strassburg.  II.  The  Vertebral 
Column  and  its  Appendages.     (6  plates.) 

Contributions  to  the  Anatomy  of  the  Eye.  By  Dr.  Ludwig  Loewe,  of  Berlin  ; 
with  the  co-operation  of  Dr.  N.  v.  Kries.     (3  plates.) 

The  Histogenesis  of  the  Retina,  together  with  Comparative  Observations  on  the 
Histogenesis  of  the  Central  Nervous  System.     By  Dr.  Ludwig  Loewe.     (1  plate.) 

Preliminary  results  of  a  larger  work  on  the  Comparative  Embryology  of 
Insects.  By  Dr.  V.  Graber,  Professor  of  Zoology  at  the  Czernowitz  University. 
(1  woodcut.) 

Vol.  XVI.,  Part  1  (issued  20tli  November,  1878)  :— 

Further  communication  on  the  Cell-spaces  of  Hyaline  Cartilage.  By  Dr. 
Albrecht  Budge.     (I  plate.) 

On  the  so-called  Hydatids  of  Morgagni.     By  Dr.  Ludwig  Lowe,  of  Berlin. 

The  Elastic  Fibres  of  the  Ligamentum  nuchas,  imder  the  action  of  Pepsin 
and  of  Trypsin.     By  Dr.  Ph.  Pfeaffer.     (1  plate.) 

On  New  Sense-organs  in  Insects,  resembling  Otocysts.  By  Dr.  V.  Graber. 
(2  plates.) 

The  Fibrillar  Structure  of  the  Nervous  Elements  of  Invertebrata.  By  Dr. 
Hans  Sclmltze,  of  Kiel.     (2  plates.) 

On  the  Changes  of  the  Serous  Epithelium  in  the  exposed  Mesentery  of  the 
Frog.     By  Dr.  Richard  Altmann,  of  (TJessen.     (3  woodcuts.) 

Contributions  to  the  Comparative  Morphology  of  the  Skeletal  System  of  Ver- 
tebrates. By  Dr.  A.  Goette,  Professor  at  Strassburg.  II.  The  Vertebral 
Column  and  its  Appendages.    (3  plates.) 

Part  2  (issued  20tli  December) : — 

Studies  on  the  Protozoa  of  Northern  Russia.  By  C.  von  Mereschkowsky,  of 
St.  Petersburg.     (2  plates.) 

The  Division  of  Cartilage  Cells :  a  contribution  to  the  Theory  of  Cell-division. 
By  W.  Schleicher.  (From  the  Histological  Laboratory  at  Ghent.)  (3  plates  and 
3  woodcuts.) 

The  Employment  of  Mixtures  of  Chromic  and  Osmic  Acids  in  Investigations 
on  the  Auditory  Organs  of  smaller  Animals.  By  Dr.  Max  Flesch,  Prosector  at 
Wiirzburg. 

Contributions  to  the  knowledge  of  the  Cell  and  of  its  Vital  Phenomena.  By 
Walther  Flemming,  Professor  at  Kiel.     (4  plates.) 

Zeitschrift  FTJR  MiKROSKOPiB,  Vol.  I.,  Part  10  (November)  : — 

The  making  of  Durable  Microscopic  Preparations  (^conclusion').    By  A.  Miinster. 

Reports  on  sixteen  articles  from  various  periodicals  relating  to  Animal 
Histology. 

Minor  Communications. — Micro-photography. — Two  new  Journals  ('  BreTiissonia ' 
and  '  American  Quarterly  Microscopical  Journal '). — New  Improvement  in  the 
Object-holder  for  Electrifying  Microscopic  Objects. — Orchella  as  a  Staining 
Mateiial. 

Bibliography. 

Jahrbtjcher  FTJR  WissENSCHAFTLiCHB  BoTANiK,  Vol.  XI.,  Part  4 : 

On  Monostroma  btitlosum,  Thur.,  and  Tetraspora  luhrica,  Ktz.     By  J.  Reinke. 

(1  plate.) 

The  Development  of  the  Embryo  of  Horse-tails.    By  R.  Sadebeck.    (3  plates.) 
Contributions    to  the   Germination  of   the    Schizseaceaa.      By    H.    Bauke. 

(4  plates.) 


BIBLIOGRAPHY.  103 

Jenaische  Zeitsohrift   piiR  Naturwissensohapt,  N.  S.,  Vol.  V., 
Part  4  :— 

Action  of  Light  and  Heat  on  Swarm-spores.     By  Pr.  E.  Strasburger. 
On  Polyembryony.     By  Dr.  E.  Strasburger.     (5  plates). 

MoRPHOLOGiscHES  Jahrbuch,  Vol.  IV.  (Parts  1-3  and  Supp.)  : — 

Anatomy  of  Isis  Neapolitana,  nov.  sp.     By  G.  v.  Koch.     (1  plate.) 
Observations  on  the  Synonymy  of  Isis  elongata,  Esper,  ■with  Isis  Neapolitana. 
By  G.  V.  Koch. 

Contributions  to  the  Anatomy  of  Chiton.     By  Dr.  H.  v.  Ihering.     (1  plate.) 
Observations  on  Neomeuia  and  on  the  Amphineura  in  general.     By  Dr.  If. 
V.  Ihering. 

Contributions  to  the  knowledge  of  the  Formation,  Fecundation,  and  Division 
of  the  Animal  Ovum.     Part  III.     By  Dr.  O.  Hertwig.     (6  plates.) 

Communications  on  Gorgonia  verrucos'i.  Pall.     By  G.  v.  Koch.     (1  plate.) 
On  the  Degeneration  of  the  Visual  Organs  in  Arachnida.     By  Ant.  Stecker. 
(1  plate.) 

On  Gloidium  qmidrifidum ;  a  new  Genus  of  Protista.  By  Prof.  N.  Sorokin. 
(1  plate.) 

The  Skeleton  of  the  Alcyonaria.     By  G.  v.  Koch.     (2  plates.) 
Communications  on  the  Ccelenterata.     On  the  Phylogeny  of  the  Antipathidce. 
By  G.  V.  Koch.     (1  plate.) 

On  the  Origin  and  Development  of  the  Elastic  Tissue.  By  Dr.  L.  Gevlach. 
(2  plates.) 

Minor  Communications,  4'c. — Are  the  Segmental  Organs  of  the  Annelida  homo- 
logous to  those  of  the  Vertebrata  ?  A  Keply  to  Dr.  Fiirbringer.  By  C.  Semper. — 
Muscle-epithelium  in  Authnzoa.  By  Dr.  O.  Kling.  (Preliminary  communica- 
tion.]— Eeview  of  H.  Grenadier's  Kesearches  on  the  Anthropod  Eye. 

Zeitsohrift  fur  Wissenschaftliche  Zoologie,  Vol.  XXXII., 
Part  1  (issued  19th  December,  1878):— 

On -the  Sexual  Organs  of  the  Cephalopoda.  First  contribution.  (4  plates.) 
By  J.  Brock. 

Researches  on  the  Structure  and  Development  of  Sponges.  Sixth  communi- 
cation :  The  Genus  Spongelia.     (4  jjlates.)     By  F.  E.  Schulze. 

Studies  on  the  Anatomy  of  Respiratory  Organs.  1.  The  Anatomy  of  the  Gill 
of  Serpiila.     By  L.  Lowe.     (1  plate.) 

MONATSBERICHT    DER     KoNIGLICHEN    PrEUSSISCHEN    AkADEMIE    DER 

WissENscHAFTEN  zu  Berlin*  (1878,  February): — 

On  the  Reflexion  of  Light  by  the  Surfaces  of  small  Crystals.  By  Herr 
Websky.    (Concluded,  with  a  plate,  in  the  July-August  number.) 

March : — 

The  Nerve-system  of  the  Chsetognatha.     By  Prof.  Langerhans. 

April : — 

On  the  Specific  Heat  of  Animal  Tissue.     By  Prof.  Rosenthal. 
Summary  of  Arachnida  collected  in  Mozambique.    By  Dr.  F.  Karsch.   (2  plates, 
containing  microscopic  details. ) 

May:— 

Investigations  of  Absorptive-spectra  (of  Inorganic  and  Organic  Bodies).  By 
Herr  H.  W.  Vogel.     (2  plates.) 


*  These  will  be  referred  to  hereafter  as  '  Monatsbericht — Berlin  Academy.' 


104  BIBLIOGR  API!  Y . 

Juue : — 

Congratulatory  Address  of  the  Academy  to  Professor  Schwann  on  his  Jubilee. 

Jul  J- August : — 

Second  communication  on  the  ^nf/toeoa  joo^(/acfmw  collected  during  the  voyage 
of  the  '  Gazelle '  round  the  World.     By  Prof.  Dr.  Th.  Studer.     (5  plates. ) 


Austria. 

SlTZUNGSBERICHTE      DER     KaISERLIOHEN     AkADEMIE     DEB     WlSSEN- 

SCHAFTEN.*  Section  I.  Mathematics — Natural  Science.  Vol.  LXXVII. 
Parts  1  and  2  (January  and  February)  : — 

The  Undulating  Nutation  of  Internodes.  A  contribution  to  the  Theory  of  the 
Longitudinal  Growth  of  Plant-stems.     By  Julius  Wiesiier. 

Note  on  the  Kelation  of  Phloroglucine  and  some  allied  Bodies  to  the  Lignified 
Cell  Membrane.     By  Julius  "Wiesner. 

On  the  Degeneration  of  the  Leaf-growth  of  some  Amygdalese  produced  by 
Species  of  Exoascus.     By  Emerieli  Kathay.     (1  plate.) 

Contributions  to  the  fuller  knowledge  of  the  Tunicata.  By  Prof.  C.  Heller. 
(6  plates). 

Parts  3  and  4  (Marcli  and  April)  :— 

On  the  Embryology  of  Ferns.     By  H.  Leitgeb.     (1  plate.) 

On  Peculiar  Openings  in  the  upper  Epidermis  of  the  Floral  Leaves  of  Frun- 

ciscea  macrantha,  Pohl.     By  M.  Waldner.     (1  plate.) 

On  the  Origin  of  the  Holes  on  the  Leaf  of  Philodendron  pertusum,  Schott. 

By  Frank  Schwarz.     (1  plate.) 

Part  5  (May)  :— 

The  Nostoc  Colonies  in  the  Thallus  of  Anthocerotese.  By  H.  Leitgeb.    (1  plate.) 

Eesearches  on  tlie  Organisation  of  the  Brain  of  Invertebrate  Animals.  Parts 
I,  and  II.  (Cephalopoda,  Tethys,  Crustacea).     By  M.  J.  Dietl.     (10  i^lates.) 

Contributions  to  the  Embryology  of  the  Chastopoda.  By  Michael  Stossich. 
(2  plates.) 

Comparative  Anatomy  of  the  Seeds  of  Vicia  and  Ervum.  By  Dr.  Gunther 
Beck.     (2  plates.) 

Kussia. 
Bulletin  de  l'Aoademie  Imperiale  des  Sciences  de  St.  Peters- 
BOURG.t  Vol.  XXIV.,  No.  4. 

The  Development  of  Cephalodia  on  the  Thallus  of  the  Lichen  Peltigera  cqMhosa, 
Hoffin.     By  M.  Babikoff.     (I  plate.) 


*  These  will  be  hereafter  referred  to  as  '  Sitzungsberichte — Vienna  Academy.' 
t  These  will  be  referred  to  hereafter  as  '  Bulletin— St.  Petersburg  Academy.' 


(     105     ) 
PKOCEEDINGS  OF  THE  SOCIETY. 


Meeting  of  11th  December,  1878,  at  King's  College,  Strand,  W.C. 
Dr.  C.  T.  Hudson,  M.A.,  LL.D.,  Vice  President,  in  the  Chair. 

The  Minutes  of  the  meeting  of  13th  November  were  read  and  con- 
firmed, and  were  signed  by  the  Chairman. 


The  following  List  of  Donations  received  since  the  last  meeting 
was  submitted,  and  the  thanks  of  the  Society  given  to  the  donors. 

From 

Two  dozen  Slides  of  Insect  Scales         Mr.  Dmis. 

A  Micrometer  ruled  with  Divisions  of  an  Inch  and  of  a  IMilli- 

metre Mr.  J.  Beck. 

A  Cabinet  for  the  Society's  Instruments  and  Apparatus  . .      . .     Mr.  Frank  Crisp. 


Dr.  Hudson  read  a  paper  (Dr.  MiUar  having  taken  the  chair  pro 
tern.)  on  a  new  species  of  (Ecistes,  sent  to  him  by  Mr.  Oxley,  which 
he  had  at  first  named  CE.  Sphagni,  but  now  proposed  to  call  by  the 
more  descriptive  name  of  CE.  umhella,  from  its  peculiar  shape,  which 
was  shown  by  coloured  drawings  (see  p.  1).  After  some  remarks  as 
to  the  nature  of  Conochilus  volvox,  which,  if  it  could  be  turned  inside 
out,  would  have  very  much  the  appearance  of  a  Melicerta,  and  com- 
mending the  paper  by  Mr.  Davis  upon  the  subject.  Dr.  Hudson  exhi- 
bited to  the  meeting  some  beautiful  coloured  trausjiareut  diagrams, 
prepared  by  himself,  of  Rotatoria,  which  he  showed  in  the  darkened 
room  by  means  of  three  duplex  lamps  placed  behind  them.  The  series 
comprised  (Ecistes  cry  stall  iiius,  Limnias  ceratcplujlli,  Limnias  annula- 
tus,  Cephalosiphon  Limnias,  Melicerta  ringens,  Melicerta  tyro  (for  which 
the  new  name  of  If.  Tubicolaria  was  proposed),  Steplianoceros  Eichornii, 
Floscularia  campanulata,  ConocMlus  volvox,  Lacinularia  socialis,  Euch- 
lanis  triquetra,  Pterodina  patina,  Actinurus  Neptunius,  Notommata  aurita, 
Pedalion  miruni,  Trochosphcera  ceqiiatorialis  (from  the  Philippine 
Islands),  and  Nais  digitata.  The  exhibition  was  accompanied  by 
brief  remarks,  in  the  course  of  which  Dr.  Hudson  observed  that  he 
thought  that  Mr.  Bedwell  in  his  excellent  pa2)er  on  ilelicertahad  credited 
that  creatiu'e  with  rather  more  intelligence  than  it  deserved.  Mr. 
Bedwell  had  stated  that  when  a  particle  came  down  to  the  mouth,  it 
descended  upon  a  kind  of  elastic  cushion,  and  he  had  credited  this 
cushion  with  a  discriminating  power  such  that  the  moment  an  object 
touched  it  there  was  an  instant  decision  and  disposal  of  it,  and  it  was 
taken  in  or  passed  to  the  right  or  left  or  rejected  according  to  its 
nature  and  fitness  for  food  or  building  purposes.  For  his  own  part, 
he  doubted  this  explanation  of  the  phenomena,  for  the  reasons  men- 
tioned in  his  paper.  A  curious  instance  was  also  related  of  what 
seemed  very  like  intelligent  action  on  the  part  of  a  specimen  of 
Floscidaria  campanulata,  which,  having  seized  and  enveloped  an  in- 
fusorion  too  large  and  straight  to  enable  it  to  withdraw  within  its 


106  PROCEEDINGS    OF    THE    SOCIETY. 

case,  was  observed  to  descend  in  a  fully  expanded  condition,  and  thus 
to  set  free  the  inconvenient  prey. 

The  thanks  of  the  meeting  having  been  voted  by  acclamation  to 
Dr.  Hudson  for  his  very  interesting  communication  and  exhibition, 
he  resumed  the  chair, 

Mr.  Badcock  thought  that  the  name  proposed  by  Dr  Hudson, 
CEcistes  umbella,  was  a  very  approj^riate  one.  He  had  found  the 
animal  on  April  dth,  1876,  at  which  time  he  showed  it  to  Mr.  Oxley 
and  others.  It  was  the  speciality  of  the  umbrella-like  structure 
which  first  drew  his  attention  to  it. 

Mr.  T.  C.  White  inquired  if  the  forms  which  had  been  exhibited 
were  from  fresh  or  brackish  water  ? 

Dr.  Hudson  said  that  all  those  they  had  seen  were  from  fresh 
water. 

Mr.  F.  H.  Ward  read  a  paper,  "  Improvements  in  the  Micro- 
spectroscope "  (see  vol.  i.  p.  326 j. 

Mr.  Thomas  Palmer  said  that,  as  far  as  the  mode  of  measurement 
was  concerned,  he  thought  he  could  claim  priority  in  the  use  of  a 
photographed  scale,  as  about  three  years  ago  he  read  a  paper  on  the 
subject,  and  exhibited  the  apparatus.  He  should  be  very  glad  to  see 
the  micro-spectroscoj)e  improved,  as  he  thought  that  it  was  not  at 
present  receiving  a  proper  amount  of  attention,  and  he  wished  Mr. 
Ward  every  success  in  his  endeavours  to  that  end.  In  honour  of  their 
late  President,  Mr.  Sorby,  some  good  work  ought  to  be  done  with  it. 
If  that  gentleman's  paper  on  "Vegetable  Chromatology "  was  more 
read  and  studied,  there  would,  he  was  sm*e,  be  more  workers  with  the 
instrument  than  at  present. 

Mr.  Crisp  said  that,  in  justice  to  Mr.  Ward,  the  meeting  should  be 
reminded  of  the  exact  words  of  the  paper  which  referred  to  the  scale, 
and  which  he  read  (see  vol.  i.  p.  329,  lines  4-6).  Apart  from  the 
question  of  the  slit,  Mr.  Ward  was  entitled,  he  thought,  to  credit  for 
the  use  he  had  made  of  the  comjiarison  prism.  The  Fellows  would 
remember  that  he  exhibited  it  at  the  May  scientific  evening,  when 
great  interest  was  taken  in  it. 

Mr.  Ward  said  he  had  tried  to  find  out  who  was  the  originator  of 
the  scale,  but  had  not  been  successful  in  doing  so,  though  he  knew  it 
was  not  new,  and  had  been  in  use  for  a  long  time  in  Germany  :  he  was 
not  aware  that  Mr.  Palmer  claimed  it. 


Mr.  Crisp  explained  the  points  of  his  paper,  "  On  some  Recent 
Forms  of  Camera  Lucida,"  a  drawing  of  that  of  Dr.  Hofmann  being 
enlarged  upon  the  black-board  by  Mr.  Stewart  (see  p.  21).  Mr.  Crisp 
observed  that  there  had  been  this  year  a  glut  of  these  instruments,  as 
there  were  now  four  before  the  Society,  viz.  Hofmann's,  Pellerin's, 
Swift's,  and  Russell's. 

Dr.  Millar  said  that  the  form  last  mentioned  was  one  devised  by 
Dr.  Russell,  of  Lancaster,  a  brief  description  of  which  he  then  gave, 
illustrated  by  a  drawing  on  the  board. 

Mr.  Beck  said  that  Mr.  Crisp  was  quite  right  in  saying  there  was 


PROCEEDINGS    OF    THE    SOCIETY.  107 

a  glut  of  these  instruments.  As  to  this  new  one  of  Hofmann's,  he 
could  not  see  what  the  si^ecial  advantage  of  it  was.  In  the  first  place 
they  had  to  take  out  the  eye-piece  because  the  reflecting  surface  was 
so  far  from  it  that  they  could  not  get  any  vision  with  it  in  its  place. 
This  he  thought  was  a  great  disadvantage.  Then,  again,  how  was  it 
proposed  to  see  the  pencil  point  ?  The  rays  were  thrown  on  a  piece  of 
glass  (A),  (see  Fig.  2,  p.  21),  and  reflected  to  (B),  and  from  that  were 
reflected  through  the  aperture  (E).  The  observer  at  (E)  looked 
through  a  piece  of  plate  glass  with  two  surfaces,  and  somewhere  on 
the  ground — upon  the  scale  on  which  the  drawing  was  made — he 
would  see  the  object.  If  they  did  not  mind  the  loss  of  light,  they 
could  get  all  the  advantages  claimed,  by  simply  making  a  hollow 
Wollaston's  camera ;  but  in  both  cases  they  had  the  disadvantages  of 
looking  through  two  surfaces  of  glass,  and  a  great  loss  of  light.  With 
all  the  changes  which  had  been  made  at  different  times,  he  still 
believed  that  if  persons  would  be  careful  to  split  the  ray  by  looking 
with  half  the  pupil  only,  and  would  also  take  the  trouble  to  properly 
modify  the  light,  there  was  nothing  better  than  the  old  form. 

Dr.  Hudson  said  that  as  one  who  very  frequently  drew  objects  from 
the  Microscope,  he  could  only  say  that  for  such  drawings  as  his  of 
living  objects  the  camera  lucida  was  nearly  useless.  The  method  he 
adopted  was  to  have  a  piece  of  glass  ruled  in  squares,  which  covered 
the  field  of  view  ;  and,  having  ruled  paper  always  at  hand,  the  object 
was  drawn  square  by  square :  and  even  the  most  active  rotifer  would 
sometimes  remain  quiet  long  enough  to  get  the  outline  correctly.  With 
an  inanimate  object  he  could  not  conceive  anything  more  easy  than 
this  method,  even  to  an  indifferent  draughtsman. 

Mr.  Ingpen  said  that  Hofmann's  camera  appeared  to  be  identical 
with  one  by  Amici,  which  was  forty  years  old  at  least.  If  the  piece 
of  glass  (B)  were  extended,  it  would  be  the  same  exactly. 

Mr,  Crisp  said  it  was  only  within  the  last  few  months  that 
Dr.  Hofmann  had  removed  part  of  the  plate  of  glass  (B),  the  restitution 
of  which  would  make  the  camera  the  same  as  Amici's,  according  to 
Mr.  Ingpen's  statement.  In  the  drawing  of  this  non-microscopic  form, 
which  appeared  lately  in  'Nature,'  it  was  shown  according  to  its 
original  design. 

Mr.  Stewart  read  a  Note  by  Mr.  A.  D.  Michael  with  reference  to 
the  finding  of  the  male  of  Cheyletus  veniistissimus  (see  vol.  i.  p.  317). 


Mr,  Crisp  called  attention  to  the  remarks  of  Professor  Adams  at 
the  meeting  of  the  Physical  Society,  on  9  th  November,  on  the  advan- 
tages possessed  by  a  portable  form  of  Dietzl's  diffraction  ajiparatus 
when  used  as  a  polarizer  for  the  Microscope  (see  p.  87). 


Mr.  Ingpen  made  some  remarks  upon  the  ^-inch  objective  exhibited 
by  Mr.  Crisp  at  the  October  meeting,*  made  by  the  Bausch  and  Lomb 


'  Journal,'  vol.  i.  p.  312. 


108  PROCEEDINGS    OF    THE    SOCIETY. 

Optical  Company,  iu  wbich  the  cover  correction  was  obtained  by 
varying  the  thickness  of  a  film  of  glycerine  placed  between  the  front 
lens  and  an  external  flat  disk  of  glass,  as  described  on  p.  251  of  the 
same  volume.  It  was  similar  in  construction  to  one  made  by  Mr. 
Gundlach,  and  exhibited  at  a  scientific  evening  in  1876,  but  showed 
considerable  imjirovement.  The  figure  and  colour  were  excellently 
corrected,  but  the  definition  could  hardly  be  considered  brilliant. 
The  cover  correction  was  remarkably  quick  and  satisfactory,  a  small 
alteration  making  all  the  difference  between  the  best  definition  and 
none  at  all.  The  apparent  angle  of  aperture  was  very  large,  but  he 
thought  part  of  it  was  "  spurious,"  probably  owing  to  reflection  from 
the  edge  of  the  glycerine  film.  The  working  distance  was  inconve- 
niently small,  and  as  the  adjustment  was  made  inside  the  objective,  it 
was  close  for  very  thin  as  well  as  for  thicker  covers.  The  method  of 
correction  was  a  very  interesting  one,  and  one  which  he  thought 
might  hereafter  form  a  new  point  of  departure  in  the  construction  of 
objectives. 

Mr.  Beck  said  that  the  Fellows  would  remember  that  recently  a 
question  was  raised  by  the  American  Microscopical  Congress  as  to 
whether  the  aliquot  parts  of  an  inch  or  of  a  metre  should  be  used  as  a 
universal  standard  of  microscopical  measurement,  anl  he  then  ven- 
tured to  suggest  that  they  should  give  the  matter  their  attention.  He 
had  considered  it,  and  he  certainly  should  recommend  that  the 
divisions  of  the  metre  should  be  adopted.  It  was  asked  at  the  time 
whether  the  scales  of  the  divisions  of  the  millimetre  could  be  obtained 
in  the  event  of  their  being  required  ;  and  having  turned  his  attention 
to  the  matter,  he  had  arranged  a  micrometer  in  which  both  scales  could 
be  seen.  Having  ruled  a  fiducial  line,  they  had  ruled  on  one  side  of 
it  yJo  and  yoVo  of  an  inch,  and  on  the  otlier  side  the  yi^  of  a  milli- 
metre, so  that  having  the  two  scales  on  one  slide  there  would  be  no 
longer  any  necessity  for  changing  the  slides  every  time  they  wanted  to 
make  a  comparison.  There  would  be  a  further  advantage  in  having 
the  two  scales  in  this  way  for  comparisons,  because  if  there  should 
happen  to  be  any  error  or  inq:)erfection  in  the  instrument  used  for 
ruling,  it  would  he  common  to  both  scales.  He  had  much  pleasure 
in  i^resenting  one  of  these  scales  to  the  Society,  and  if  any  Fellow 
found  anything  which  could  be  improved  he  should  be  happy  to 
adopt  the  suggestion. 

A  Discussion  took  place  between  Mr.  J.  Mayall,  jun.,  and  Dr. 
Edmunds,  as  to  the  immersion  prism  referred  to  by  the  latter  at  the 
October  meeting  (vol.  i.  p.  309),  and  which  Mr.  Mayall  claimed  to 
have  been  originated  and  suggested  by  him,  a  claim  which  Dr. 
Edmunds  on  the  other  hand  disputed. 


The  following  were  exhibited  :— 

Dr.  Hudson  : — Seventeen  coloured  transparent  drawings  of  rotifers. 

Mr.  F.  H.  Ward  : — (1)   The   micro-spectroscope   and  aj)paratus 


PROCEEDINGS    OF    THE    SOCIETY.  109 

referred  to  in  his  paper,  and  (2)  two  sections  of  broom,  double 
stained  by  himself,  which  were  much  admired. 

Dr.  Millar: — The  camera  lucida  devised  by  Dr.  Eussell. 

Mr.  Crisp  : — (1)  Hofmaun's  camera  lucida.  (2)  Swift's  ditto. 
(3)  Dietzl's  diffraction  apparatus.  (4)  Stein's  Infusoria,  Part  III. 
(the  Flagellata).  (5)  Micro-photographs  of  botanical  subjects,  by 
De  Bary. 

Mr.  J.  Mayall,  jun. : — (1)  His  two  modifications  of  Dr.  Woodward's 
"  new  device,"  in  which  the  four  exposed  surfaces  of  the  prism  are 
utilized  by  cutting  them  at  various  angles,  so  as  to  approximate  the 
angle  of  the  illuminating  rays  to  the  semi-aperture  of  the  objective 
likely  to  be  used.  One  is  an  ordinary  prism  so  cut,  but  with  circular 
top  for  convenience  of  rotation,  and  mounted  at  the  end  of  a  brass 
tube  with  wide  slots  for  the  free  intromission  of  light  perpendicularly 
to  each  face.  The  other  is  a  nearly  hemispherical  lens  with  the  four 
faces  cut  on  the  spherical  surface,  and  mounted  on  a  rod  attached  to 
the  centre  of  this  surface.  (2)  A  nearly  hemispherical  lens  and  a 
small  semi-cylinder  mounted  conveniently  for  immersion  illumination. 


New  Fellows : — The  following  gentlemen  were  elected  Fellows 
of  the  Society :— Edwin  W.  Alabone,  M.D.,  M.E.C.S.,  and  John  Simp- 
son Harrison,  Esq. 


Meeting  of  8th  Januart,  1879,  at  King's  College,  Strand,  W.C. 
J.  W.  Stephenson,  Esq.,  F.R.A.S.  (Treasuber),  in  the  chair. 

The  Minutes  of  the  meeting  of   11th  December  were  read  and 
confii'med,  and  were  signed  by  the  Chairman. 


The  following'  List   of  the   Donations   received   since   the   last 

meeting  was  submitted,  and  the  thanks  of  the  Society  given  to  the 

donors. 

From 

Abbe,  Dr.  E. — Die  OptLchen  Hiilfsmittel  der  Mikioskopie. 
(Extracted  from  '  Bericht  iiber  die  wissenschaftlielie  Ap- 
parate  auf  der  Londoner  Internationalen  Ausstellung  im 
Jahre,  1876') The  Author. 

Badham,   Dr.    0.   D. — The   Esculent   Funguses   of   England. 

2nded.     1863 Mr.  Frank  Crisp. 

Cooke,  Dr.  M.  C.—Grevillea.     Vols.  I.-VI.     1872-8        ..      ..  Ditto. 

Dtiby,  Julien.- — De  la  recherclie  Microscopique  du  Sang  au  point 
de  vue  Me'dico-legal.    1876.    (Extracted  from  the  '  Annales 

de  la  Societe' Beige  de  Microscopic ') The  Author. 

„  „  Ce  que  c'est  qu'une  Diatome'e.  1877.  (Ex- 
tracted from  the  '  Bulletin  de  la  Socie'te  Beige  de  Micro- 
scopie '  for  1877),  and  five  other  papers        Ditto. 


The  Chairman  having  requested  the   Fellows   to   appoint   two 
auditors  of  the  accounts  for  the  past  year,  Mr.  Goodinge  (proposed 


110  PROCEEDINGS    OF    THE   SOCIETY. 

by  Mr.  Curties,  and  seconded  by  Dr.  Matthews),  and  Mr.  Curties 
(proposed  by  Mr.  Guimaraens,  and  seconded  by  Mr.  Michael),  were 
duly  elected. 

Mr.  Stewart  gave  a  resume  of  a  paper  by  Mr.  W.  J.  Sollas,  M.A., 
F.G.S.,  "  Observations  on  Dacti/localyx  pumiceus  (Stuchbury),  with  de- 
scription of  a  new  variety,  D.  Stucliburyi"  the  chief  points  of  interest 
in  which  were  illustrated  by  diagrams  drawn  ujjon  the  black-board. 
The  photographs  and  drawings  which  accompanied  the  paj)er  were 
also  handed  round  for  inspection,  (This  paper  will  appear  in  the 
April  number.) 

Dr.  Matthews  said  that  he  had  been  giving  a  good  deal  of  atten- 
tion lately  to  the  subject  of  corals,  madrej)ores  and  allied  forms,  and 
on  examining  them  he  thought  he  had  found  some  evidences  of  para- 
sitism. At  the  base  of  each  of  many  specimens,  he  had  found  that 
there  was  a  rough  mass  of  stony  material  which  he  at  first  cast  aside. 
Some  time  afterwards  he  was  led  to  examine  these  parts  in  the  hope 
of  finding  diatoms  or  foraminifera  uj^on  or  in  them,  and  he  then  dis- 
covered the  curious  fact  that  each  coral  was  more  or  less  based  upon 
a  sjjonge,  and  that  it  appeared  to  be  a  real  case  of  parasitisai.  He  at 
first  thought  that  he  had  made  a  discovery,  but  further  inquiry  showed 
that  there  had  been  a  paper  written  upon  the  subject  by  Mr,  Carter.* 
He  (Dr.  Matthews)  found  that  this  state  of  things  was  shown  in  nine 
cases  out  of  ten  of  the  sj)ecimens  examined  by  him.  There  were, 
however,  some  other  specimens  which  displayed  clear  evidence  of 
having  been  bored  by  a  sponge.  He  had  also  found  that  certain 
sponges  had  become  associated  with  some  of  the  madrej^ores  in  such 
a  manner,  as  to  suggest  the  idea  of  a  kind  of  mutual  parasitism  or 
commensalism,  and  also  that  in  some  cases  the  whole  sponge  had 
become  enclosed  and  the  cavity  filled  by  sarcode  and  gemmules,  the 
whole  being  fused  together  in  such  a  way  that  it  was  hardly  possible 
to  tell  by  the  Microscope  where  the  gemmules  ended  and  the  corallum 
began ;  in  fact,  the  fusion  of  the  two  seemed  very  complete  and  extra- 
ordinary, the  thin  layer  of  corallum  extending  completely  over  the 
sponge.  He  had  found  also  some  foraminifera,  but  had  not  yet  had 
time  to  examine  them.  Mr.  Carter  in  his  paper  did  not  mention  any 
coral  larger  in  size  than  \  inch,  and  this  was  described  as  being  wholly 
on  the  surface  of  the  sponge.  He  thought  the  matter  was  worth 
mentioning,  and  although  it  might  be  only  one  fact  added  to  the  great 
heaj),  it  might  some  day  be  of  use  when  clealt  with  by  other  hands. 

Mr.  Stewart  said  that  very  commonly  before  these  corals  arose  as 
a  branching  stem  they  spread  out  in  a  thin  layer,  from  which  the 
corallum  afterwards  arose.  They  were  very  often  fixed  to  a  loose 
kind  of  oolitic  rock,  which  was  very  friable  and  easily  broken  down, 
and  it  was  easy  to  imagine  how  this  kind  of  cap  might  involve  a 
sponge.  If  what  had  been  described  occurred  in  this  manner,  he 
should  hardly  be  disposed  to  call  it  a  case  of  parasitism.  In  some 
kinds,  however,  such  as  the  Hyalonema  or  glass  rope  sponge,  they 
*  See  vol.  i.  p.  288. 


PROCEEDINGS    OF    THE    SOCIETY.  Ill 

frequently  met  with  a  kind  of  true  parasitism.  It  was  also  quite  a 
common  thing  to  find  Hydrozoa  and  other  things  attached  to  the 
sj)ouges. 

Dr.  Matthews  said  that  he  spoke  with  diffidence  on  the  question  of 
parasitism.  He  had  a  number  of  specimens  to  show  after  the  meeting, 
and  which  he  thought  would  help  to  elucidate  the  question. 

On  the  motion  of  the  chairman,  a  vote  of  thanks  was  passed  to 
Mr.  Sollas  for  his  paj)er,  the  chairman  saying  he  thought  it  had  not 
been  of  any  less  interest  from  having  been  the  means  of  eliciting  the 
very  interesting  communication  of  Dr.  Matthews. 


Dr.  J.  Edmunds  read  a  "  Note  on  a  Revolver  Immersion  Prism  for 
Sub-stage  Illumination,"  the  subject  being  illustrated  by  diagrams,  and 
by  the  exhibition  of  the  apparatus  described  (see  p.  32).  A  discussion 
ensued  between  Mr.  Lettsom,  Mr.  Mayall,  and  Dr.  Edmunds. 


Mr.  John  Mayall,  jun.,  read  a  paper  "  On  Immersion  Illuminators," 
various  kinds  of  which  he  exhibited  in  illustration  of  the  paper  (seep.  27). 

The  Chairman  inquired  if  Mr.  Mayall  had  tried  mounting  objects 
otherwise  than  in  balsam,  because  it  appeared  to  him  that  water  might 
be  a  very  good  medium. 

Mr.  Mayall  said  he  had  been  working  mainly  upon  objects  in 
Canada  balsam,  but  he  had  sojne  time  ago  the  opportunity  of  exami- 
ning some  of  Professor  Tyndall's  bacteria,  which  were  in  water,  and 
he  then  saw  very  clearly  with  the  immersion  what  Mr.  Dalliuger  had 
the  greatest  difficulty  in  making  out. 

The  Chairman  thought  that  the  greater  diffijrence  between  the 
refractive  index  of  diatom  silica  and  water,  as  compared  with  balsam, 
would  probably  render  the  structure  more  visible  if  water  was  used. 

Mr.  Mayall  said  he  remembered  to  have  observed  that  such  was 
the  case. 

The  Chairman  said  that  they  had  another  paper  by  Mr.  Mayall, 
"  The  Aperture  question,"  and  one  by  himself,  "  On  a  Catojitric  Im- 
mersion Illuminator  "  (see  p.  36),  which  must  be  taken  as  read,  owing 
to  the  press  of  business  before  the  meeting. 


Mr.  Crisp  explained  the  views  of  Mr.  Julien  Deby  in  the  paper  he 
had  sent  entitled  "  Is  not  the  rotiferous  genus  Pedalion  of  Hudson 
synonymous  with  Hexartlira  of  Ludwig  Schmarda?"  Dr.  Hudson's 
drawings  of  Pedalion  and  that  of  Schmarda  being  laid  before  the 
meeting. 

Mr.  Stewart  read  part  of  a  paper  by  Mr.  Kitton,  on  "  The  Thallus 
of  Diatoms,"  accompanied  by  comments  on  the  views  expressed  by 
Dr.  Lanzi  and  Mr.  Kitton  (see  p.  38). 


Mr.  Crisp  gave  an  account  of  the  observations  of  Professor  Graber, 
of  Czernowitz,  on  some  new  sense-organs  (supjjosed  to  be  auditory) 


112  PROCEEDINGS    OF    THE   SOCIETY. 

in  insects,  and  suggested  that  they  would  form  a  highly  interesting 
subject  for  the  further  examination  of  microscopists,  the  more  par- 
ticularly as  Professor  Graber  stated  that  for  want  of  time  he  had  been 
unable  to  complete  the  observations  that  required  to  be  made  in 
order  to  establish  their  exact  character.  The  organs  described  were 
drawn  on  the  black-board  by  Mr.  Stewart  (see  p.  45,  and  Plate  IV. 
Figs.  1,  1  a,  1  b,  2,  and  2  o). 

Dr.  Matthews  inquired  if  the  hairs  were  supposed  to  perform  the 
function  of  otoliths. 

Mr.  Stewart  regarded  the  mode  of  nerve-termination  of  these 
organs  as  presenting  the  closest  resemblance  to  that  of  the  human 
auditory  apparatus.  He  thought  there  seemed  in  all  cases  a  special 
provision  to  prevent  the  otolith  from  touching  the  hairs.  If  they 
examined  it  in  the  bony  fish  they  would  find  that  there  was  an  otolith 
convex  on  the  side  facing  the  brain,  and  this  would  come  in  contact 
with  the  hairs,  but  for  the  fact  that  they  also  constantly  found  deep 
grooves,  which  seemed  as  if  they  were  to  ensure  that  the  otolith 
should  be  in  as  close  a  connection  as  possible  without  resting  upon  them. 

The  Chairman  proposed  a  vote  of  thanks  to  Mr.  Crisp  for  his  very 
interesting  description  of  the  important  observations  referred  to,  and 
to  the  authors  of  the  other  papers  which  had  been  read  that  evening, 
which  was  carried  unanimously. 


The  List  of  Fellows  nominated  for  election  as  members  of  the 
Coimcil  at  the  ensuing  annual  meeting,  was  read  in  accordance  with 
the  44th  bye-law. 

The  following  objects  were  exhibited : — 

Mr.  Ingpen  : — (1)  An  old  camera  lucida,  of  the  form  designed  by 
Amici,  in  which  the  image  of  the  object  is  twice  reflected,  first  by  an 
opaque,  and  then  by  the  first  surface  of  a  transparent  mirror;  the 
method  being  identical  with  that  of  Dr.  Hofman  described  at  the  last 
meeting.  (2)  Also  another,  by  Amici,  in  which  the  image  of  the 
object  was  reversed  by  a  right-angled  prism. 

Dr.  Matthews: — Specimens  exhibiting  parasitism  of  a  coral  on  a 
sponge. 

Mr.  F.  H.  Ward  : — Sections  of  mistletoe  from  an  apple-tree — 
double  stained. 

Mr.  Crisp  : — (1)  The  Sorby  miniature  micro-spectroscope  (see 
J).  81).  (2)  Kecklinghausen  and  Meyer's  pathological  micro-photo- 
graphs. (3)  Specimens  of  microscopic  printing  issued  by  the 
Security  Printing  Company.  (4)  Muhr's  "  Wall  Charts "  of  the 
anatomy  of  the  head  of  insects. 

Mr.  Heneage  Gibbes  was  elected  a  Fellow  of  the  Society,  and 
five  gentlemen  were  proposed  for  election  at  the  next  meeting. 

Walter  W.  Eeeves, 

Assist.-Secretartj. 


^" ~ ^r" 

ir     Vol.  II.  No.  2.]         APRIL,  1879.  [   price  3s.    ^^ 

Journal 


OF   THE 


Royal 
Microscopical  Society; 


CONTAINING    ITS 


TRANSACTIONS    AND    PROCEEDINGS, 

AND   OTHER    INFORMATION   AS   TO 

INVERTEBRATA  AND  CRYPTOGAMIA, 
EMBRYOLOGY,  HISTOLOGY,  MICROSCOPY,  &c. 

Edited^  under  the  direction  of  the  Publication  ComniitteCy  by 

FRANK  CRISP,  LL.B.,  B.A.,  F.L.S,, 

ONE  OF  THE  SECRETARIES  OF  THE  SOCIETY. 


.1  WILLIAMS    &    NORGATE, 

\^l!^  LONDON   AND   EDINBURGH.  ^(^  / 


H3  ^^ — — uj^C^ 

PRINTED   BY    WILLIAM    CLOWES    AND   SONS,]  [STAMFORD   STREET    AND   CHARING    CKOSS. 


H 


JOURNAL 

OF  THE 

EOYAL  MICKOSCOPICAL  SOCIETY. 

VOL.  II.    No.  2. 


CONTENTS. 


Tkansaotions  of  the  Society —  pagb 

IX.  The  Pkesident's  Address.     By  H.  J.  Slack,  F.G.S.          ..  113 

X.  Observations  on  Dact^looalyx  pumioeus  (Stutchbuuy), 
WITH  A  Description  of  a  New  Variety,  Dactylooalyx 
Stutchbubyi.     By  W.  J.  Sollas,  M.A.,  F.G.S.,  &c.,  &c. 

(Plates  V.-VIII.) 122 

XI.  The  Aperture  Question.     By  J.  Mayall,  jun.,  F.K.M.S.  . .  134 

Notes  and  Memoranda             ..          ..          ..          ..          ..  137 

Cells,  and  their  Vital  Phenomena 137 

Picro-caimine  for  Cell-nuclei 138 

Influence  of  the  different  Colours  of  the  Spectrum  on  Animals  and  Plants..  138 

Colonel  Woodward  on  the  Oil-Immersion  Objectives  and  the  Apertometer  . .  140 

Diffraction  Experiments  with  Pleurosigma  angulatum 141 

Brain  of  Invertehrates        112 

•     Poison  Apparatus  and  Anal  Glands  of  Anfg 142 

Parthenogenesis  in  Bees     143 

Hermaphroditism  in  Perlidx " 144 

Employment  of  Mixtures  of  Chromic  and  Osmic  Acids  for  Histological 

Purposes       144 

Microscopical  Research  under  Difficulties       145 

Degeneration  of  the  Visual  Organs  in  Arachnida ..  146 

Ascent  and  Circulation  of  the  Sap 147 

Growth  of  tJie  Rout  of  Phanerogams 149 

Removal  of  Air  from  Microscopic  Specimens 150 

Immersion  Illuminators 151 

Phosphorescence  of  the  Flesh  of  Lobsters 151 

Species  of  Marine  Crustacea  hi  Lake  Erie     152 

Gigantic  Isopod  of  the  Deep  Sea       152 

Limicolous  Cladocera l^^ 

New  Cryptogamic  Journals       1^4 

Unit  of  Micrometry 1^4 

The  Tomopteridss.        l-''^ 

Abnormal  Sexual  Organs  in  ike  Horse-Leech •      ••  156 

The  Early  Development  of  Equisetacese 157 

A  New  Rotifer — Anurssa  longispina        157 

Trichinx       1^^ 

Trichina-phobia  at  Berlin '  1^^ 

Organogenic  Researches  on  the  Capsule  of  Mosses  and  on  the  Embryo  of 

some  Polypodiacese «      1^^ 


Notes  and  Memoranda — continued.  pack 

The  " Micro-Megascope" ^"" 

Chlorophyll ••      ••      ^^^ 

Function  of  Chlorophyll  in  the  green  Planarix 161 

Development  and  Metamorphoses  of  Txnix      162 

Another  Method  of  Staining       163 

Size  of  Society  Screw  and  of  Slides 163 

The  Termination  of  the  Visceral  Arterioles  in  Mollusca        164 

Hxmocyanin  a  neio  Substance  in  the  Blood  of  Hie  Octopus 164 

Chromatic  Function  in  the  Octopus 165 

Neio  Classification  of  Thallophytes 166 

Fungoid  Diseases  of  Plants       167 

Organization  of  Hygrocrocis  arsenicus,Bieb 169 

Tiie^'Plastids"  of  the  lower  Plants 170 

Stiiining  for  Fungi     ..• , 17" 

Spines  of  Echini • 171 

The  Locomotor  System  of  Medusa     171 

Tetrapteron  volitans -  17^ 

The  Algx  of  the  White  Sea        173 

Achromatic  Lenses      173 

Development  of  Spongilla  fluviatilis 174 

Morphology  and  Systematic  Position  of  the  Spongida 177 

Sponge- spicules 177 

Gloidium,  a  neio  genus  of  Protista 179 

Preparation  of  Microscopic  Aquatic  Animals 180 

The  Postal  Microscopical  Society 180 

Life- History  of  the  Diatomarex        181 

Movements  of  Diatoms  and  Oscillatoriese         182 

The  Use  and  Abuse  of  Diatoms  as  Test  Objects       183 

Measurement  of  the  Amplification  of  Optical  Instruments     184 

Liicosporangium,  a  new  genus  of  Phceosporese       186 

Eeproduction  of  Ulvacese 186 

Nosloc-colonies  in  Anthocerotese 187 

Support  for  the  Head  in  Drawing  with  tlie  Camera  Lucida        187 

Aleoholic  Fermentation      187 

Bacteria  in  the  Poison  of  Serpents 189 

Flagellated  Organisins  in  Eats' Blood      190 

Dtceptive  Appearances  produced  by  Reagents 191 

Preparation  of  Red  Blood-corpuscles        191 

Apparatus  for  Determining  the  Angle  of  tlie  Optic  Axes  of  Crystals  with  the 

Microscope 191 

Artificial  Crystals  of  Gold 193 

The  Vertical  Illuminator 194 

Reproduction  of  Noctiluca         195 

Bibliography       ..          ..          ..          ..          ..          ..          ..          ..  196 

Proceedings  of  the  Society    ..  ..  ..  ..  ..  ..211 


Meetings  of  the  Society. 


1879. 
Wednesday,  April  9. 
„  May  14. 

„  June  11. 


1879. 
Wednesday,  October  8. 

„  November  12. 

„  December  10. 


HENRY  CROUCH'S 

FIEST- CLASS    MICKOSCOPES 

(JACKSON    MODEL), 

OBJECTIVES,  AND  ACCESSORIES. 


Catalogue,  fully  Illustrated,  on  Application. 


HENRY  CEOUCH,  66,  Barbican,  London,  E.C. 


JOURNAL 

OF    THE 

ROYAL  MICROSCOPICAL  SOCIETY. 

APEIL,  1879. 


TEANSACTIONS  OF  THE  SOCIETY. 


IX.—TJie  President's  Address.    By  H.  J.  Slack,  F.G-.S. 
(Bead  12th  Februanj,  1879.) 

I  AM,  unfortunately,  quite  unable  to  follow  in  the  footetejjs  of 
Mr.  Sorby,  who,  upon  two  occasions,  brought  before  you  in  his 
Annual  Addresses  important  original  work,  highly  gratifying  to 
those  who  value  and  desire  to  increase  the  scientific  standing  of  this 
Society.  Failing  in  this,  it  seemed  most  desirable  to  select  a  few 
points  of  interest  for  your  consideration,  arising  out  of  recent 
invention  and  observation. 

First,  I  would  mention  the  introduction  of  the  oil  lenses  sug- 
gested by  Mr.  Stephenson,  and  constructed  under  the  direction  of 
Professor  Abbe  by  Herr  Zeiss,  of  Jena.    The  objects  of  this  inven- 
tion are  twofold ;  first,  to  do  away  with  the  troublesome  necessity 
for  making  corrections  with  the  screw  collar  introduced  by  Andrew 
Eoss,  and  secondly,  to  obtain  the  largest  angle  of  aperture  with 
a  good  working  distance.     By  selecting  an  oil,  or  mixture  of  oils 
having  the  same  refractive  power  as  the  covering  glass,  it  wa» 
expected  that  a  fixed  correction  would  suffice  for  any  thickness. 
When  the   cover  was  thicker,   as  the  working  distance   of  the 
objective  remained  unchanged,  there  would  be  a  thinner  stratum 
of  oil  used  upon  the  immersion  principle,  and  when  the  cover 
was  thinner  the  oil  stratum  would  be  thicker.     After  many  trials. 
Professor  Abbe  found  oil  of  cedar  wood  had  very  nearly  the  requi- 
site properties  when  the  illumination  was  with  oblique  light,  and 
was  improved  for  direct  light  by  an  admixture  with  oil  of  fennel 
seed.     The  glass  made  for  Mr.  Stephenson  fully  answered  expec- 
tation.     It  had  according  to  his  description  a  balsam  angle  of 
113^,  its  power  was  rather  more  than  one-ninth,  and  the  only 
correction  it  needed  was  a  change  in  the  length  of  the  Microscope 
tube  from    10  inches  to   12   when  very  thin   covers  were  em- 
ployed.    One  result  of  using  objectives  of  this  construction,  taken 
in  connection  with  Professor  Abbe's  account  of  the  way  in  which 

VOL.    II.  I 


114  Transactions  of  the  Society. 

lined  objects  can  be  viewed,  or  lined  appearances  produced,  has 
been  to  throw  fresh  doubt  as  to  the  correspondence  between  actual 
structure,  and  optical  effects  of  this  description ;  and  we  are  thrown 
back,  as  I  pointed  out  in  reference  to  insect  scales  long  ago,  upon 
the  necessity  of  making  various  experiments,  and  of  reasoning 
from  the  best  analogies  we  can  obtain  in  the  interpretation  of  the 
appearances  we  see.  Amongst  those  who  have  experimented  with 
the  oil  lenses  I  may  mention  Dr.  Pigott,  who  speaks  of  a  No.  15 
as  a  "  magnificent  glass." 

It  was  not  found  by  Mr.  Dallinger,  whose  researches  require 
the  highest  and  most  efficient  optical  aid,  that  the  oil  objectives 
showed  anything  he  could  not  see  with  the  Powell  and  Lealand 
glasses  he  usually  employed,  but  he  at  once  admitted  and  praised 
the  great  facility  with  which  they  could  be  used.  He  has  since 
obtained  excellent  effects  by  using  oil  of  cedar  wood  with  Powell 
and  Lealand's  newest  I,  yV»  ^^^1  yV?  and  expresses  great  admiration 
for  a  new  wet  and  dry  i^V  by  the  same  makers. 

By  the  kindness  of  Mr.  Baker,  I  had  an  opportunity  of  trying  an 
\  and  tV-  The  latter  I  found  a  splendid  glass,  remarkable  for  the 
ease  with  which  it  displayed  difficult  objects,  and  requiring  only  a 
film  of  oil  to  connect  it  with  the  slide  cover.  The  a  had  such  a 
large  working  distance  that  it  required  a  little  puddle  of  the  oil, 
and  on  this  account  could  only  be  employed  with  the  Microscope  in 
a  vertical  position.  I  am  told  that  these  glasses  ^e  not  all  alike  in 
this  respect.  ^'     •<, 

The  '  American  Quarterly  Microscopical  Journal '  for  January, 
1879,  contains  a  letter  from  Professor  Abbe,  explaining  that  owing 
to  a  mistake  several  |ths  have  been  made  with  a  balsam  angle  of 
107°  to  109^  only,  instead  of  114  to  116,  as  they  should  have 
been.  He  also  states  these  objectives  are  composed  of  "  four  sepa- 
rate lenses,"  and  not  three,  as  Professor  H,  L.  Smith  supposed. 

It  seems  probable,  from  Mr.  Dallinger's  experiments,  and  a  few 
made  by  myself,  that  opticians  may  be  able  to  furnish  us  with 
objectives  that  can  be  corrected  for  either  oil  or  water ;  but  if  this 
cannot  be  satisfactorily  accomplished,  it  is  not  likely  that  the  oil 
lenses  will  supersede  the  water  ones,  though  they  have  obviously 
some  decided  advantages  for  special  purposes. 

The  fine  performances  of  the  large-angled  glasses  of  the  best 
makers,  and  the  results  obtained  with  the  extreme  angles  of  the  oil 
lenses,  have  led  in  some  quarters  to  a  belief  that  great  angles  are 
good  for  all  purposes ;  but  there  can  be  little  doubt  that  this  will  be 
found  a  mistake,  and  that  glasses  of  small  and  moderate  angles, 
with  fine  corrections,  will  still  be  needed  for  much,  and  probably 
for  most,  valuable  work.* 

*  See  Dr,  Pigott's  paper  "  On  the  Invisibility  of  Minute  Refracting  Bodies 
caused  by  Excess  of  Aperture,"  *  M.M.  J.,'  February,  1875,  p.  55. 


The  President's  Address.     By  H.  J.  Slack.  115 

Mr.  Dallinger  has  pointed  out  that  fine  dry  lenses  are  still 
necessary  for  many  cases  in  which  the  use  of  fluids  is  objectionable, 
and  this  brings  us  to  the  consideration  of  the  direction  in  which  we 
must  look  for  further  progress. 

It  is  now  several  years  since  Dr.  Pigott  called  attention  to  the 
practical  importance  of  the  residual  errors  of  the  best  objectives 
then  made,  and  he  proved  experimentally  that  with  the  existing 
materials  it  was  possible  to  reduce  them.  Since  then  important 
advances  have  been  made,  both  with  dry  and  wet  lenses,  and  it  is 
probable  that  for  a  further  advance,  to  any  important  extent,  the 
optician  must  be  supplied  with  fresh  materials. 

Professor  Abbe  says,  "  The  impossibility  of  removing  each  chro- 
matic diiierence  of  spherical  aberration  has  its  root  in  the  circum- 
stance that,  in  the  kinds  of  crown  and  flint  glass  at  present  provided, 
the  dispersion  always  goes  hand  in  hand  with  the  mean  index  of 
refraction,  in  such  a  way  that  the  higher  dispersion  is  attached  to 
the  highest  index.  The  outstanding  aberrations  might  be  com- 
pletely, or  very  nearly,  compensated,  if  an  optical  material  were 
provided  in  which  a  relatively  lower  refractive  index  were  united 
with  a  higher  dispersion,  or  a  higher  refractive  index  with  a  rela- 
tively smaller  dispersion.  It  would  then  be  possible  by  combining 
such  materials  with  the  ordinary  crown  and  flint  glass  to  remove 
the  chromatic  and  spherical  aberrations  which  are  partly  discon- 
nected, and  thus  fulfil  the  essential  conditions  arising  from  the 
chromatic  difierence."  * 

Professor  Abbe  also  remarks  upon  the  very  small  number  of 
persons  engaged  in  the  manufacture  of  glass  for  optical  purposes, 
and  upon  the  few  substances  that  have  hitherto  been  employed  in 
its  preparation.  Looking  to  the  present  conditions  of  manufacturing 
industry,  which  ofier  the  largest  gains  to  those  who  can  produce  at 
the  lowest  price  articles  required  in  great  quantities,  it  is  not  pro- 
bable that  purely  commercial  considerations  will  induce  anyone  to 
devote  attention  to  the  demands  of  science  for  new  kinds  of  glass 
or  substitutes  for  glass,  and  the  task  is  not  likely  to  be  undertaken 
unless  through  the  help  of  private  munificence,  or  State  aid. 

Besides  glasses,  which  are  chiefly  silicates  of  potash,  soda,  and 
lead,  with  a  little  alumina  or  lime,  &c.,  there  seems  a  probability 
that  a  class  of  compounds  resembling  precious  stones  may  come  into 
optical  use.  IM.  Feil,  a  celebrated  manufacturer  of  optical  glass, 
and  M.  Fremy  have  succeeded  in  artificially  producing  rubies  and 
sapphires,  alumina  minerals  of  high  refractive  power,  and  it  is  not 
impossible  some  quite  new  compounds  may  be  formed.  When  Sir 
David  Brewster  experimented  with  jewel  lenses,  he  spoke  very  highly 
of  garnet,  which  is  a  compound  of  three  or  four  silicates,  chiefly  of 

*  '  Die  Optischeu  Hiilt'sunttel  der  Mikroskopie,'  von  Dr.  E.  Abbe,  Professor 
un  der  Universitat  zu  Jena,     liraunschweig,  1878. 

I  2 


116  Transactions  of  the  Society. 

alumina  and  lime.  If  the  optician  were  supplied  with  fresh  sub- 
stances possessing  the  requisite  properties,  we  might  not  only  have 
objectives  of  more  perfect  corrections,  but  higher  powers  with  flatter 
curves  and  larger  lenses. 

Passing  from  objectives  to  their  employment  and  performance, 
we  find  Professor  Abbe  dealing  with  the  conditions  necessary  for 
the  resolution  of  close-lined  and  analogous  objects,  Mr.  Dallinger 
measuring  the  flagella  oi  Bacterium  termo  and  finding  them  less  than 
the  200,00Uth  of  an  inch,  and  Dr.  Pigott  exhibiting,  by  remagnifi- 
cation,  the  image  of  a  spider  line  diminished  to  the  one-millionth  of 
an  inch. 

If  we  consider  the  application  of  high  powers  to  natural  history, 
it  is  an  interesting  question  how  far  the  existing  optical  means 
enable  the  structure  and  rank  of  many  of  the  minuter  organisms  to 
be  discovered,  and  how  far  down  in  the  scale  sexual  generation  can 
be  affirmed,  or,  with  probability,  assumed. 

Professor  Haeckel  places  amongst  his  Protista,  eight  classes 
of  creatures,  including  Amoeba,  Flagellata,  Diatoms,  &c.,  and 
affirms  of  the  whole  list  "  that  the  most  important  physiological 
characteristic  of  the  kingdom  Protista  lies  in  the  exclusively  non- 
sexual propagation  of  all  the  organisms  belonging  to  it."  *  With 
regard  to  this  statement,  it  may  be  mentioned  that  in  1863  Dr. 
Wallich  published  a  remarkable  series  of  observations  on  the  form 
of  Amoeba  he  discovered  in  a  Hampstead  pond,  and  named  villosa 
from  its  having  a  permanent  villous  organ  protruding  from  one 
part.  He  stated  that  "  one  of  the  most  remarkable  amongst  the 
most  novel  and  varied  characters  of  the  Amoebae  consists  in  the 
vesicle,  in  which  the  true  nucleus  is  contained,  having  been  found 
to  be  distinctly  membranous  in  some  individuals."  He  noticed 
also  "  a  clear  nucleolus,"  and  inquired  whether  the  appearances 
presented  justified  the  belief  that  the  creature  possessed  "  a  germ 
cell  and  sperm  cells."  t 

In  April,  1875,1  Messrs.  Dallinger  and  Drysdale  described  a 
series  of  facts  in  the  life-history  of  certain  flagellate  monads,  includ- 
ing a  sexual  union,  a  division  of  nucleus,  and  formation  of  germs  at 
first  so  minute  as  to  be  separately  invisible,  and  then  developing  by 
several  changes  into  the  parental  form.  A  magnification  of  2600 
diameters  sufficed  for  watching  these  processes,  and  made  the  nuclei 
appear  about  one -eighth  of  an  inch  in  their  shortest  diameter.  One 
of  the  creatures  in  its  most  globular  condition  had,  with  that  power, 
an  apparent  longest  diameter  exceeding  one  inch,  and  the  shorter 
diameter  a  httle  under  an  inch.  If  we  compare  these  dimensions 
with  those  of  Bacterium  termo  magnified  4000  diameters,  in  Mr. 

*  '  History  of  Creation,'  vol.  ii.  p.  69. 
t  '  Ann.  N.  H.,'  May,  1863. 
X  '  M.  M.  J.,'  May,  1875. 


The  Presidenfs  Address.    By  H.  J.  Slack.  117 

Dallinger's  drawing  represented  in  the  September  number  of  the 
new  Journal,  *  we  find  the  latter  creature's  body  composed  of  two 
oval  beads,  each  one  seeming  only  about  the  size  of  the  nucleus  of 
the  just  mentioned  flagellate  monad,  though  the  magnification  is 
1400  diameters  greater.  How  much  smaller  living  creatures  may 
exist  it  is  not  possible  to  say,  but  with  those  of  these  dimensions  we 
can  scarcely  expect  any  mode  of  vision  furnished  by  the  Microscope  to 
enable  the  processes  of  their  germ  formation  to  be  traced.  Another 
difficulty  of  dealing  with  these  organisms  arises  from  the  fact  that 
it  is  only  by  unintermittent  watching  for  a  long  time  and  under  a 
variety  of  conditions  that  the  whole  cycle  of  their  life  changes 
can  be  made  known.  Mr.  Dallinger  has  shown  in  the  case  of 
monads  that  the  same  species  in  difierent  stages  of  development 
present  very  difierent  aspects  and  behave  in  very  difierent  ways. 
The  minute  bacteria  found  to  be  capable  of  producing  in  animals 
the  splenic  disease  which  the  French  call  san^  de  rate,  has  been 
found  by  other  observers  able  under  certain  conditions  to  branch 
like  the  mycelium  of  a  mould ;  and  in  M.  Pasteur's  book  '  La  Biere ' 
will  be  found  many  illustrations  of  dissimilar  growths  of  ferments, 
and  fungi  under  difierent  circumstances.  After  recounting  many 
interesting  experiments,  M.  Pasteur  remarks  that  in  the  dust  of  a 
laboratory  in  which  fermentations  are  studied,  there  are  many  germs 
which  give  rise  to  organisms  which  it  is  impossible  to  distinguish 
fi-om  alcoholic  ferments,  although  they  do  not  possess  the  properties 
of  those  bodies. 

In  endeavouring  to  avoid  the  error  of  lumping  together  a 
number  of  small  organisms  under  a  common  heading,  implying  a 
very  low  stage  of  development,  attention  should  be  paid  to  any 
indications  that  may  be  obtained  from  their  external  organs, 
although  their  internal  structure  may  defy  scrutiny.  An  or- 
ganism furnished  with  cilia  in  constant  vibration  is  in  that 
respect,  and  may  be  in  others,  below  another  in  which  cihary 
motion,  to  use  the  words  of  the  *  Micrographic  Dictionary,'  "  is 
interrupted  at  intervals,  apparently  under  the  influence  of  a  will." 
Of  course,  the  term  "  will  "  is  only  employed  to  express  a  remote 
analogy.  The  difierence  appears  to  be  that  the  ceaseless  motion  in 
one  case  responds  to  some  contiuuous  necessity,  possibly  that  of 
respiration,  while  the  intermittent  one  responds  to  a  less  frequent 
need,  such  as  going  in  search  of  food.  The  "  springing  monad  "  of 
Messrs.  Dalhnger  and  Drysdale,t  so  called  from  its  peculiar  habit 
of  coiling  and  uncoiling  one  of  its  flagella  with  a  darting  motion, 
not  unlike  the  vorticella,  carrying  the  body  with  it,  evidently 
possesses  an  instrument  superior  to  the  simple  cilium,  and  the  same 
may  be  said  of  the  "  hooked  monad  "  of  these  observers,  a  creature 
"  with  a  persistent  hook-like  flagellum."    The  "  calycine  monad,"  to 

*  '  Juumal  R.  M.  S.,'  vol.  i.  No.  4.  f  '  M.  M.  J.,'  vol.  x.  p.  245. 


118  Transactions  of  the  Sociehj. 

wliicli  reference  has  already  been  made,  is  in  its  normal  state  like  a 
cup,  terminating  in  a  slender  pointed  stem.  It  has  nuclear  bodies 
and  two  large  "  eye  spots,"  with  the  strange  "  rhythmical  opening 
and  shutting  "  seen  by  these  observers  in  some  other  monads.  It 
is  provided  with  four  long  flagella,  and  the  authors  say,  its  mode 
of  locomotion  is  "a  graceful  gliding  through  the  water,  the 
flagella  moving  so  often  and  so  rapidly  as  to  render  their  detection 
impossible  when  the  monad  is  at  its  swiftest.  They  could  roll  over 
on  their  long  axis,  and  change  the  direction  of  their  motion  with 
lightning-like  rapidity,  and,  however  crowded  the  field,  not  the 
slightest  approximation  to  collision  occurred."  In  this  case  the 
creature  is  big  enough  for  some  important  internal  organs  to  be 
seen,  but  had  it  been  too  smaU  for  this,  or  had  none  been  open  to 
detection,  would  not  its  remarkable  and  varied  powers  of  locomotion 
have  afforded  fair  ground  for  suspecting  that  it  ought  not  to  be 
ranked  among  the  simplest  unicellular  bodies  ? 

Before  passing  to  another  topic,  a  protest  may  be  admitted 
against  a  not  uncommon  practice  of  describing  some  of  the  lowest 
living  things  as  composed  of  a  little  mass  of  "  homogeneous  proto- 
plasm." Is  it  not  true,  whenever  magnification  reasonably  pro- 
portioned to  the  size  of  any  organism  can  be  applied,  its  proto- 
plasm, so  far  from  being  "  homogeneous,"  exhibits  granulation,  or 
particles  difiering  in  refractive  power,  and  presumably  in  chemical 
properties  from  the  mass  ? 

The  progress  of  discovery  certainly  leads  to  the  belief  that  the 
processes  and  functions  of  the  higher  animals  are  developments  of 
what  is  found  low  down  in  the  scale.  In  a  lecture  "  On  the  Phe- 
nomena of  Life  common  to  Animals  and  Plants,"*  Claude  Bernard 
said,  "  the  principle  of  vital  unity  dominates  in  the  entire  history  of 
animals  and  plants,"  and  he  characterized  "  nutrition"  as  "  continuous 
generation."  In  another  passage  he  said,  "  At  the  origin  of  every 
nutritive  or  generative  phenomenon  there  is  an  organized  agent, 
egg,  germ,  cell,"  and  up  to  the  present  time  the  Spontaneous  Gene- 
ration Controversy  has  resulted  in  showing  that  there  are  no  known 
means  of  obtaining  any  manifestations  of  new  life,  excepting  as  the 
products  and  results  of  previous  life,  acting,  and  acted  upon,  by 
appropriate  surroundings.  There  is,  however,  another  controversy 
still  going  on,  in  which  the  Microscope  is  indispensable,  which  has 
very  wide  and  important  bearings  upon  a  variety  of  scientific  ques- 
tions, and  which  has  a  better  chance  of  being  finally  settled. 

This  controversy  relates  to  M.  Pasteur's  explanation  of  certain 
facts  and  appearances  belonging  to  fermentation.  In  1861,  and 
since,  M.  Pasteur  has  been  led  by  various  experiments  to  divide  a 
group  of  living  organisms  into  two  classes,  which  he  designates 
aerohies  and  anaerohies,  the  former  requiring  for  their  existence 

*  'Kevue  Scientifiquc,'  26th  September,  187i. 


The  President's  Address.    Btj  H.  J.  Slack,  119 

and  growth  the  presence  of  free  oxygen,  and  the  latter  able  to  dis- 
pense with  it,  provided  they  are  brought  in  contact  with  a  ferment- 
able substance  from  which  they  can  obtain  the  oxygen  they  need 
by  a  process  of  decomposition — the  latter,  he  affirms,  to  be  ferments. 
Septic  vibrions  he  finds  killed  by  free  oxygen,  and  these  come 
under  his  designation  of  anaerohies.  In  other  cases,  and  notably 
in  yeast  plants,  he  notices  a  capability  of  living  in  either  state ; 
and  in  the  last  or  anaerohic  one,  they  act  as  ferments. 

Before  proceeding  further  with  M.  Pasteur's  researches,  it  will 
be  well  to  bear  in  mind  what  takes  place  in  the  life  processes  of  the 
higher  chlorophyll-containing  plants,  and  we  shall  then  be  able  to 
see  what  relation  these  aerohies  and  anaerohies  bear  to  them. 

The  experiments  and  observations  of  M.  Corenwinder,  extending 
and  confirming  opinions  expressed  by  M.  Th.  de  Saussure,  and 
supported  thirty  years  ago  by  M.  Garreau,*  show  that  the 
respiratory  process  of  plants  is  constant,  and  like  that  of  animals 
carried  on  by  absorption  of  oxygen  and  exhalation  of  carbonic  acid, 
and  that  the  absorption  of  carbonic  acid  with  retention  of  carbon 
and  emission  of  oxygen  is  "  a  veritable  digestion."  The  respiratory 
acts  belong  to  the  nitrogenous  matter  of  the  plants,  and  the  carbon 
digestion  to  the  chlorophyll,  and  it  depends  essentially  upon  the 
influence  of  Hght,  being  most  active  during  direct  exposure  to  solar 
rays  and  diminishing  as  the  light  is  weakened.  The  carbou  carried 
oft'  in  the  respiratory  action  comes  from  the  supply  obtained  by  the 
digestive  and  assimilative  processes. 

We  learn  from  M.  Pasteur  that  the  moulds  Penicillium  and 
Aspergillus,  and  the  "mother  of  wine,"  Mycodermi  vini,  are 
capable  of  living  in  either  of  the  states  named,  and  he  describes  a 
variety  of  experiments  showing  these  facts,  and  he  remarks  upon 
them,  "  We  are  constrained  to  admit  that  the  production  of  alcohol 
and  carbonic  acid  with  the  help  of  sugar,  in  a  word,  alcoholic  fer- 
mentation, are  chemical  acts  connected  with  the  plant  life  of  cells  of 
very  divers  natures,  and  that  they  appear  at  the  moment  these  cells 
are  no  longer  able  to  burn  freely  the  materials  of  their  nutrition  by 
the  efiect  of  respiration,  that  is  to  say,  by  absorption  of  free  oxygen, 
and  that  they  accomplish  their  life  by  utilizing  oxygenated  sub- 
stances like  sugar  and  combustible  bodies,  which  give  out  heat  in 
their  decomposition.  The  fennent  character  then  presents  itself 
to  us,  not  as  pecuHar  to  this  or  that  being,  or  this  or  that  organ, 
but  as  a  general  property  of  the  living  cell;  a  character  always 
ready  to  manifest  itself,  and  actually  doing  so  when  its  life  is  no 
longer  accomplished  under  the  influence  of  free  oxygen,  or  of  a 
quantity  of  that  gas  sufficient  for  all  the  acts  of  nutrition."  f 

M.  Pasteur  gives  drawings  of  the  appearance  of  various  cells 

*  See  '  Revue  Sc!entifique,'  Ibt  August,  1874. 
t  'LaBiere,'  pp.  113,  114. 


120  Transactions  of  the  Society. 

grown  under  the  two  conditions.  They  might  be  taken  for  dif- 
ferent species,  and  no  mere  microscopic  examination  would  suffice 
to  show  what  they  were. 

Speaking  of  the  pecuHar  effects  of  yeast  and  other  ferments,  he 
observes  that  "  there  is  only  a  slight  relation  between  the  weight  of 
the  yeast  formed  and  the  weight  of  sugar  decomposed;  with  all 
other  known  beings  the  weight  of  the  nutritive  matter  assimilated 
is  of  the  same  order  of  quantity  as  the  weight  of  the  aliments 
brought  into  play.  The  discrepancy  where  it  exists  is  relatively 
slight.  Such  is  not  the  life  of  yeast.  For  a  weight  a  of  yeast 
formed,  the  weight  of  the  sugar  decomposed  is  10  a,  20  a,  100  a, 
and  even  more." 

The  growth  and  generation  of  ferments  in  mineral  media  are 
regarded  by  M.  Pasteur  as  having  "  a  great  physiological  interest." 
He  says,  "  They  demonstrate,  among  other  results,  that  all  the  pro- 
tein matter  of  yeasts  may  have  their  origin  in  the  vital  activity  of 
cells  putting  in  action  hydrocarbonous  substances  without  the 
influence  of  light  or  free  oxygen — or  with  free  oxygen  in  the  case 
of  the  aerobics — together  with  salts  of  ammonia,  phosphates,  and 
sulphates  of  potash  and  magnesia.  It  might  even  with  rigour  be 
admitted  that  a  similar  effect  is  produced  in  the  higher  plants. 
What  serious  reason  can  be  invoked  in  the  present  state  of  science 
for  not  considering  this  effect  as  general  ?  It  would  not  be  illogical 
to  extend  the  results  we  speak  of  to  all  plants,  and  to  believe  that 
the  protein  matters  of  plants,  and  perhaps  even  of  animals,  are 
formed  exclusively  by  the  activity  of  cells  acting  on  the  ammoniacal 
salts  and  the  mineral  salts  of  the  sap,  or  of  the  plasma  of  the  blood 
and  the  hydrocarbonous  matters,  of  which  the  formation  in  the 
higher  plants  only  requires  the  aid  of  the  chemical  forces  of  green 
light. 

"  According  to  this  view  the  formation  of  protein  substances  is 
independent  of  the  great  act  of  reduction  of  carbonic  acid  under 
the  influence  of  light.  ...  As  in  plant  production  by  a  hydro- 
carbonous matter  in  a  mineral  mediiun,  the  hydrocarbonous  matter 
may  vary  greatly,  and  we  comprehend  with  difficulty  how  it 
reduces  itself  to  its  elements  before  serving  for  the  composition  of 
the  protein  matters,  we  may  hope  to  obtain  as  many  distinct 
protein  bodies,  and  even  celluloses,  as  there  are  hydrocarbonous 
matters."  M.  Pasteur  states  that  he  is  engaged  in  experiments  of 
this  description.  He  further  remarks  that  if  solar  radiation  is 
indispensable  for  the  decomposition  and  formation  of  the  proximate 
principles  of  the  larger  plants,  certain  lower  ones  can  do  without  it, 
and  still  form  a  variety  of  the  most  complex  substances,  so  that 
life  in  inferior  forms  might  exist  even  if  sunlight  disappeared. 

Objections  have  been  made  to  M.  Pasteur's  theory  of  the  action 
of  ferments  by  various  authorities,  and  the  controversy  is  still  going 


The  Presiclenfs  Address.    By  H.  J.  Slack.  121 

on  in  the  French  Academy.  Schiitzenberger,  in  his  work  on  Fer- 
mentation, says,  "  Yeast  sets  up  alcohoHc  fermentation  in  a  solution 
of  pure  sugar  in  the  absence  of  all  trace  of  oxygen,  but  without 
developing ;  this  is  contrary  to  the  affirmation  of  M.  Pasteur  that 
fermentation  is  bound  up  with  the  organization  of  the  yeast,  or  is 
a  phenomenon  correlative  to  the  vital  activity  of  the  cells." 

Full  explanations  on  this  point  are  given  by  M.  Pasteur  in  '  La 
Biere.'  I  will  cite  one  passage  (p.  239),  in  which  he  says,  "  In  order 
to  multiply  itself  in  a  fermentable  medium,  without  the  presence  of 
oxygen  gas,  the  cells  of  yeast  must  be  extremely  young,  full  of  life 
and  health,  still  under  the  influence  of  the  vital  activity  they  owe 
to  the  free  oxygen  which  assisted  to  form  them,  and  which  perhaps 
they  have  stored  up  for  a  time.  When  older  they  have  much 
difficulty  in  reproducing  themselves  without  air,  and  they  age 
more  and  more  quickly :  if  they  continue  to  multiply,  it  is  under 
a  bizarre  and  monstrous  form.  When  still  older  they  remain 
absolutely  inert  in  a  medium  deprived  of  free  oxygen.  It  is  not 
that  they  are  dead :  usually  they  rejuvenesce  rapidly  if  sown  in  the 
same  hquid  after  it  has  been  aerated." 

The  lines  of  inquiry  suggested  by  M.  Pasteur  may  lead  to 
many  valuable  results.  It  is  obvious  that  the  chemist  can  compose 
a  great  variety  of  nutrient  fluids  in  which  many  of  the  lower 
organisms  can  be  grown.  Certain  mineral  matters,  compounds  of 
ammonia  to  supply  nitrogen,  and  hydrocarbons  that  may  be  varied 
to  almost  any  extent,  ofl'er  the  means  of  experiments  presenting 
different  conditions  and  likely  to  lead  to  different  results. 

Unless  new  methods  can  be  devised,  it  will  evidently  be  a  waste 
of  time  to  seek  amongst  the  simplest  organisms  for  any  transition, 
or  change  of  dead  matter  into  living  matter  without  the  inter- 
vention of  a  living  cell ;  but  as  the  highest  organisms  are  orderly 
and  co-ordinated  aggregations  of  simple  ones,  the  smallest  living 
particle  capable  of  growth,  reproduction  and  decay,  may,  when 
rightly  questioned,  elucidate  some  of  the  profoundest  problems  with 
which  the  biologist  has  to  deal. 


122  Transactions  of  the  Society. 

X. — Observations  on  Dactijlocalyx  pumiceus  (Stutchhury),  with  a 
DescriiMon  of  a  New  Variety,  Dactylocalyx  Stutehhuryi. 

By  W.  J.  SoLLAs,  M.A.,  F.G.S.,  &c.,  &c. 

(^Eead  8fh  January,  1879.) 

Plates  V.,  VI.,  VII.,  and  VIII. 

The  specimens  of  Dactylocalyx  which  came  under  the  examination 
of  Stutchhury  were  two,  hoth  of  which  belonged  originally  to  the 
Bristol  Museum ;  of  these,  one,  a  very  fine  and  complete  vasiform 
example,  is  still  preserved  there  intact ;  of  the  other,  which  is  the 
describer's  type,  the  Bristol  Museum  only  possesses  a  part,  the 
other  part,  comprising  a  half  of  the  originally  vasiform  specimen, 
together  with  a  piece  broken  from  the  remaining  half,  having  been 
exchanged  with  the  British  Museum  for  a  half  of  a  specimen  of 
Hyalonema  japonica  (Grey). 

Thus  there  now  remains  at  Bristol  a  complete  specimen  of 
Dactylocalyx,  together  with  a  fragment  of  the  type,  and  having 
had  occasion,  while  arranging  the  collection  of  sponges  in  the 
Museum,  to  examine  this  material  anew,  I  came  across  some  fresh 
facts  relating  to  it  which  appear  to  me  worth  recording. 


DESCRIPTION  OF  THE  PLATES. 
Plate  V. 
Fig.  1. — Dactijlocalyx pumiceus ;  var.  Stutchburyi.     Lateral  view.      X  0"321. 
Fig.  2. — The  same,  seen  from  above,     x  0'3i. 

Plate  VI. 

Fig.  1. — Dactylocalyx  Stutehhuryi.     Seen  obliquely  from  below.      X  0'37. 

Fig.  2. — A  lantern-spine,  supporting  an  acerate  spicule;  the  ends  of  the 
spicule  are  not  represented  in  the  drawing,     x  50. 

Figs.  3  and  4. —  Similar,  but  more  usual  form  of  lantern-spines,  exhibiting 
their  ordinary  reticulate  character,     x  50. 

Fig.  5. — Sexradiate  spicule,  from  the  surface  of  the  perforating  tubule  in 
D.  Stutehhuryi.      X  50. 

Fig.  6. — Quadriradiate  spicules,  common  in  the  dermal  layer  of  D.  Stutehhuryi. 
X  50. 

Plate  VII.  {Dactylocalyx  pumiceus). 

Fir.  1. — Fusiform  acerate  spicule  of  the  outer  surface  X  15;  a,  middle  of 
spicule  X  150. 

Fig.  2. — Sexradiate  dermal  spicule  with  distal  ray  suppressed,     x  50. 

Fig.  3. — Smaller  acerate  spicule,  capitate  at  both  ends,      x  25. 

Fie.  4. — Sexradiate  dermal  spicule,  with  one  of  the  liorizontal  arms  bent  back- 
wards, and  all  except  the  proximal  ray  with  capitate  ends,      x  50. 

Fig.  5. — Typical  sexradiate  of  the  dermal  layer,     x  50. 

Fig.  6. — Sharply-spined  fibre  of  the  secondary  netwoik.     x  100. 

Fig.  7. — Secondary  network  formed  on  a  framework  of  large  sexradiate 
spicules.     X  50. 

Fig.  8. — Dermal  sexradiate,  with  long,  wavy,  bianched  rays,      x  50. 

Fig.  9.— Small  sexradiates,  from  the  interior  of  the  body-network;  «,  with 
pointed,  6,  with  capitate  ends.      X  50. 


JOUR.  R.MIC.  SOC.VOL.ir  Pl.V. 


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JOITR.  B..  MIC.  SOC.VOLn.  Pl.^. 


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JOUR.  R.MIC.   SOC.VOL.lI.Pl.YII. 


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Spicules   of   Dacrtylocalyx    pumiceus 


JOUR.  R.  MIC.  SOC.VOL.n.Pl  wr. 


W  J  S0IU.S  del.  MintarM  Bi-o=  i«ij>. 

3picules    of   Daclylocalyx    pumiceu-S   &   13.   Stu-chbixryi . 


On  Badijlocahjx  pumiceus  (Stutchhunj).     By  W.  J.  Sottas.   123 

Dactylocdlyx  pumieeus  (Stutchbury).* 

Outer  surface. — The  under  or  outer  surface  of  this  widely 
expanded  vasiforni  sponge  is  folded  into  a  number  of  ridges  and 
deep  grooves,  which  radiate  in  an  irregular  sinuous  fashion  from 
the  base  towards  the  edge  of  the  vase,  the  ridges  frequently 
anastomosing  laterally  in  their  course,  so  as  to  circumscribe  the 
grooves,  which  thus  seldom  extend  continuously  for  more  than 
2  inches  in  length,  and  never  beyond  2^  inches.  The  greatest 
depth  attained  by  these  channels  is  fl"-  The  exterior  of  the 
ridges  is  marked  by  circular  openings  from  which  more  or  less 
cylindrical  tubes  are  continued  inwards  into  the  sponge  at  right 
angles  to  its  surface ;  these  tubes  either  open  directly  into  the 
excurrent  canals  which  we  shall  mention  presently,  or  more  fre- 
quently, after  branching  once  or  twice,  lose  themselves  in  the  large 
meshes  of  the  skeletal  network. 

On  the  inner  surface  of  the  cup  a  number  of  round  holes  occur, 
each  elongated  a  little  in  a  radiate  direction,  looking  obliquely 


Fig.  10.- — Spicule  involved  in  siliceous  material,  which  has  failed  to  com- 
pletely invest  one  ray.  At  the  point  where  the  ray  has  been  k-ft  bare  it  appears 
to  have  been  reabsorbed,  so  that  its  extremity  is  quite  disconnected  with  the 
centre  of  the  spicule,     x  50. 

Fig.  11. — An  octahedral  node  of  the  young  fibre,     x  50. 

Fig.  12. — Dermal  sexradiate  spicule,     x  50. 

Fig.  l.S. — Sexi'adiate  spicule  from  the  interior  of  the  body  skeleton,  very 
similar  in  size  and  form  to  those  which  furnished  the  framework  of  the  secondary 
network  in  Fig.  7,  PI.  VIII.     X  50. 

Fig.  14. — Dermal  sexradiate  spicule,     x  50. 

Fig.  15. — Dermal  sexradiate  with  distal  rays  pointed  and  horizontal  rays 
capitate,     x  50. 

Fig.  16. — Dermal  sexradiate  with  the  distal  ray  reduced  to  a  capitate  ter- 
mination,     x  50.     a,  distal  ray  on  a  larger  scale.      X  100. 

Fig.  17. — Sexradiate  spicule  with  very  long  shaft,  probably  so  disposed  in  the 
sponge  that  the  horizontal  rays  projected  some  distance  beyond  the  dermal  sur- 
face.    X  50. 

Fig.  18. — Curved  small  form  of  acerate  spicule,  capitate  at  both  ends,     x  50. 

Fig.  19. — Two  flesh  spicules  cemented  on  to  the  skeletal  fibre. 

Plate  VIII. 

Fig.  1. — Young  fibres  oi  D.  pumiceus,  showing  their  position  relative  to  the 
dermal  spicules.      X  100. 

Fig.  2. — Dermal  layer  of  D.  pumiceus,  with  the  acerate  spicules  omitted.  The 
young  fibres  are  represented  in  their  relative  position  beneath  it. 

Fig.  3. — Young  fibre  of  D.  pumiceus.     x  100. 

Fig.  4. — A  part  of  tiie  network  from  the  base  of  B.  Stutchhuryi.    x  50. 

Fig.  5. — A  single  mesh  of  the  basal  network  filled  in  with  secondary  fibres. 
X50. 

Fig.  6. — Young  fibres  of  D.  pumiceus.     x  100. 

Fig.  7. — Secondary  reticulation  of  "darning"  fibres  from  D.  pumiceus.      x  50. 


*  Stutchbury,  'Proc.  Zool.  Soc.,'  1841,  pt.  ix.  p.  SQ\  'Ann.  and  Mag.  Nat. 
Hist.,'  vol.  ix.  p.  504.  Bowerbank,  'Proc.  Zool.  Soc.,'  18()!),  p.  77,  pi.  iii.  fig.  1. 
Carter,  '  Ann.  and  Mag.  of  Nat.  Hist.,'  ser.  4,  vol.  xii.  p.  363. 


124 


Transactions  of  the  Society. 


upwards  and  towards  the  axis  of  the  cup,  and  frec[uently  prolonged 
at  the  sides  into  a  little  gutter,  as  in  Fig.  1 . 


Fig.  1. 


Fig.  2. 


0,  osculo ;  c,  excurrent  canal ;  g,  groove. 

These  holes  are  the  mouths  of  the  excurrent  canals,  which 
descend  into  the  walls  of  the  sponge,  passing  especially  into  the 
ridges  of  the  outer  surface,  where,  after  branching  once  or  oftener, 
they  terminate,  either  in  small  round  openings  on  the  surface,  or 
by  losing  themselves  in  the  coarse  meshes  of  the  skeleton. 

In  a  similar  manner  the  grooves  or  gullies  of  the  outer  surface 
are  prolonged  into  tubes  which  tend  towards  the  inner  surface  of 
the  cup,  ramifying  in  their  course  till  they  open  into  the  excurrent 
canals,  or  lose  themselves  in  the  large  meshes  of  the  skeletal 
network. 

Thus  the  only  connection  between  the  excurrent  canals  which 
open  on  the  inside  of  the  cup,  and  the  deep  gullies  of  the  exterior, 
is  by  means  of  very  minute  intervening  canals,  or  through  the 
large  meshes  of  the  skeleton. 

The  ridging  and  grooving  of  the  exterior,  combined  with 
the  excavation  of  the  ridges  by  the  excurrent  canals,  produce  a 
folding  of  the  sponge  wall,  very  similar 
to  that  which  occurs  in  the  Ventricu- 
lites and  other  fossil  sponges.  In  both 
cases  the  folding  serves  to  give  great 
strength  to  the  sponge  wall,  and  a  large 
inhalent  surface  at  a  great  economy  of 
space. 

Section  across  the  wall  of        The  whole  arrangement  reminds  one 
D.  pumceus  (|  natural  size) ;  ^^so  of  what  is  Seen  on  a  smaller  scale  in 

r  r,  exterior  ridges  ;  1 1,  inter-    tt  ?•  777-         i  1  -i 

voning  furrows ;  e  e,  excurrent  Haiisarca  lotmlaris,  where  likewise  we 
canals  occupying  interior  of  have,  according  to  the  beautiful  sec- 
"^g«-  tions  of  F.  Eilhard  Schultze,*  incurrent 

canals  opening  externally  and  branching  within  into  minute  canals, 
which  again  gather  together  to  form  the  large  excurrent  canals 
that  open  on  the  interior  of  the  sponge.  Here,  however,  having  a 
fresh  specimen  before  us  complete  in  all  its  parts,  we  can  see  the 
ampullaceous  sacs  on  the  ultimate  ramifications  of  the  incurrent 
canals,  and  so  understand  clearly  the  mechanism  by  which  water  is 

*  '  Zeitschriit  f.  wiss.  Zool.,'  Bd.  xxviii.  Taf.  I.  fig.  8 ;  Taf.  II.  fig.  15 ; 
Taf.  III.  fig.  10. 


On  Dactylocalyx  pumiceus  (Stutchhury).     By  W.  J.  Sollas.    125 

caused  to  enter  at  the  inhalent  orifices,  to  pass  through  the  fine 
canals,  and  finally  to  empty  itself  out  of  the  sponge  by  the 
excurrent  tubes.  But  having  regard  to  analogy,  one  cannot  but 
feel  that  a  similar  mechanism  once  existed  in  our  specimens  of 
Dactylocalyx :  the  minute  canals  which  unite  together  the  ultimate 
ramifications  of  the  excurrent  and  incurrent  tubes,  were  the  seat  of 
those  ampullaceous  sacs  which  by  driving  the  water  continually 
out  at  one  end  of  the  minute  canals,  caused  a  continual  influx  at 
the  other ;  the  single  current  entering  at  one  inhalent  apertui-e  was 
immensely  subdivided  to  supply  a  large  number  of  ampullaceous 
sacs ;  the  many  currents  leaving  those  sacs  were  united  together  to 
flow  out  at  an  exhalent  aperture  in  a  single  stream. 

Skeleton. — On  examining  the  skeleton  of  the  sponge  with  the 
naked  eye,  one  observes  a  regular  network  of  fibres,  the  meshes  of 
which  may  be  called  "  large  "  meshes  to  distinguish  them  from 
others  of  which  we  speak  next ;  similarly,  the  fibres  may  be  known 
as  "  large  "  fibres. 

Under  the  Microscope  the  large  fibres  are  found  to  consist  of  a 
network  of  much  finer  fibres,  and  with  correspondingly  small 
meshes.  These  are  what  are  usually  understood  as  the  meshes  and 
fibres  of  the  skeleton,  so  that  the  terms  may  be  used  without  any 
distinctive  quaUfication. 

The  large  meshes  may  possibly  serve  in  some  cases  to  give 
passage  to  the  minute  ramifications  of  the  water-canals  of  the 
sponge. 

Dermal  layer. — Bowerbank  states  that  he  could  not  find  any 
trace  of  dermal  structure  in  the  half  of  the  type  specimen  which  he 
examined,  but  predicts  that  when  a  specimen  perfect  enough  to 
show  it  is  obtained,  it  will  present  the  characters  of  the  same 
structure  in  Dactylocalyx  Prattii  or  D.  Masuni.  Unable  to 
believe  that  the  work  of  cleaning  so  large  a  specimen  as  ours  could 
have  been  so  thoroughly  accomplished  as  to  have  removed  all 
vestiges  of  the  dermal  skeleton,  I  set  to  work  to  find  the  missing 
structure,  being  at  the  same  time  well  assured  that  if  found  it 
would  not  in  a  Hexactinellid  sponge  Hke  D.  pumiceus  present  the 
same  characters  as  in  Lithistids  such  as  D.  Prattii  and  D.  Masoni. 
Nor  did  I  have  long  to  look,  for  down  in  a  tubule,  which  com- 
pletely perforated  the  sponge,  a  perfect  forest  of  long  acerate 
spicules  was  seen,  bristling  erectly  from  the  surface,  and  forming, 
together  with  a  layer  of  sexradiate  spicules,  the  structure  of  our 
search.  This  tubule,  as  already  remarked  completely  perforates 
the  wall  of  the  sponge,  passing  freely  from  one  side  to  the 
other ;  it  thus  difiers  from  an  ordinary  excurrent  or  incurrent 
canal,  and  in  all  probability  represents  a  part  of  the  surface  of 
the  edge  of  the  sponge,  which  became  simply  enclosed  by  growth 
and  not  incorporated  with   the  body  substance.     If  this  is  so, 


126  Transactions  of  the  Society. 

one  will  have  no  difficulty  in  explaining  why  a  dermal  layer  was 
found  here  and  nowhere  else — not  in  a  single  excurrent  canal,  nor 
on  the  sides  of  the  exterior  grooves ;  although,  had  it  at  any  time 
existed  in  these  places,  it  must  almost  certainly  have  left  some  trace 
of  its  existence  behind.  The  truth  is,  the  dermal  layer  must  have 
been  confined  to  the  general  surface  of  the  sponge,  and  covered  the 
walls  of  our  tubule,  because  these  were  originally  a  part  of  the 
general  surface,  and  only  by  accident,  as  it  were,  came  to  assume  a 
tubular  form.  When  the  specimen  was  cleaned  the  dermal  layer 
would  readily  be  removed  from  exposed  surfaces,  but  would  easily 
escape  destruction  in  this  secluded  recess.  The  absence  of  a  dermal 
layer  from  the  sides  of  the  grooves  on  the  under  surface  is  most 
noteworthy,  and  leads  one  to  infer  that  the  dermal  layer  on  the 
under  surface  was  continued  from  ridge  to  ridge,  so  as  to  roof  over 
the  intervening  gullies  without  in  any  case  dipping  into  them. 

The  piece  of  the  sponge  exhibiting  the  dermal  layer  was  care- 
fully cut  out  and  variously  mounted  for  microscopical  examination. 

If  we  commence  our  observation  of  a  transverse  section  from  its 
outermost  face,  we  shall  see  first  the  distal  ends  of  a  number  of 
acerate  spicules,  which  when  traced  inwards  for  a  distance  of  about 
a  quarter  of  an  inch,  are  found  to  enter,  normally  to  its  surface,  the 
skeletal  network  of  the  sponge,  penetrating  through  its  meshes  for 
about  the  same  distance  as  they  project  beyond  it.  Next  we  find 
just  outside  the  skeletal  network  a  dermal  layer  of  sexradiate 
spicules,  each  with  four  long  horizontal  arms  extended  in  the  plane 
of  the  dermal  layer,  and  witli  the  two  remaining  arms  at  right 
angles  to  it,  the  distal  one  short  and  frequently  aborted,  the 
proximal  one  descending  perpendicularly  into  the  meshes  of  the 
skeleton  like  a  little  rootlet  into  the  soil.  The  horizontal  arms  do 
not  appear  to  be  arranged  into  a  regular  square-meshed  network. 

Beneath  the  dermal  layer  we  reach  the  outermost  layer  of  the 
reticulate  skeleton,  consisting  of  framework  spicules  only  just 
connected  together  by  siliceous  cement.  The  skeletal  layer  succeed- 
ing this  is  still  very  young,  so  that  its  fibres  still  retain  an  open 
lace-like  character,  not  having  yet  become  filled  up  with  the 
siliceous  deposit,  which  subsequently  in  the  third  or  fourth  layers 
renders  them  solid  throughout.  In  the  third  and  fourth  layers  then 
the  fibres  have  assumed  the  form  of  solid  homogeneous  threads 
which  only  differ  from  those  of  the  quite  adult  skeleton  by  their 
greater  smoothness  and  less  abundant  tuberculation. 

Acerate  fusiform  spicules  (Plate  VII.,  Figs.  1,3,  and  18). — These 
are  cylindrical  in  the  middle  and  taper  very  gradually  towards  each 
end,  till  they  terminate  in  extremities  of  remarkable  tenuity.  The 
longest  complete  example  measured  i"  in  length  and  0"0015"  in 
breadth ;  but  these  dimensions  may  be  slightly  exceeded  in  some 
other  cases,  though  one  cannot  say  so  definitely,  owing  to  the  fact 


On  Bactylocalyx  pumiceus  (ShUchhury).     By  W.  J.  SolJas.   127 

that  the  great  majority  of  these  spicules  are  incomplete  at  one  end, 
and  thus  incapable  of  exact  measurement.  In  some  cases  the  end 
has  been  apparently  broken  off,  in  others  it  appears  to  have  yielded 
to  some  solvent  action,  either  after  the  death  of  the  sponge,  or 
quite  as  possibly  during  its  hfe ;  for  the  sponge  appears  to  have 
been  alive  when  first  procured,  and  the  eroded  umbones  of  Anodon 
and  Unio  shells  show  that  such  contemporaneous  solution  is  not  an 
unknown  phenomenon  in  the  animal  kingdom. 

The  ends  of  the  acerates  are  roughened  by  minute  spines, 
which  give  them  a  ragged  appearance,  and  their  tenuous  extre- 
mities are  pointed.  Associated  with  them  are  other  acerate 
spicules  (Figs.  3  and  18)  which  differ  in  a  number  of  minor 
characters ;  thus  the  latter  are  usually  smaller  than  the  former, 
more  often  curved,  and  though  sometimes  pointed,  yet  very 
frequently  capitate  clavately  at  one  or  both  ends.  The  larger 
acerates  are  excavated  by  a  well-defined  axial  canal  which,  however, 
never  exhibits  any  trace  of  a  sexradiate  cross  in  any  part  of  its  course. 
I  have  repeatedly  examined  a  large  number  of  perfect  acerate 
spicules  with  a  view  to  making  sure  on  this  point,  and  1  am  able  to 
state  therefore  with  full  confidence  that  none  of  them  show  the 
least  signs  of  a  sexradiate  character.*  Instead  of  being  aborted 
sexradiate  spicules,  they  are  from  my  point  of  view  the  least  modi- 
fied descendants  of  the  simple  acerate  spicules  of  which  the  early 
ancestral  sponge  was  composed ;  the  sexradiates  on  the  other  hand 
having  departed  the  most  widely  from  the  original  type. 

The  coarse  meshes  where  they  open  at  the  surface  of  the 
sponge,  appear  as  the  circular  mouths  of  minute  tubes,  walled  in 
with  the  large  fibre,  and  reminding  one  somewhat  of  the  structure 
of  Aplirocallistes.  It  is  into  the  large  fibre  surrounding  these  tubes, 
but  not  into  that  forming  their  floor,  that  the  acerate  spicules  are 
inserted,  which  thus  leave  the  tubes  unencumbered  within,  but  form 
a  beautiful  fringe  to  them  externally. 

Sexradiate  sincules  of  the  dermal  layer. — These  are  remarkably 
variable  in  all  their  characters  ;  the  most  typical  form  being  that  of 
Fig.  5,  Plate  VII.  This  possesses  the  full  complement  of  six  rays, 
four  lying  on  the  surface  of  the  sponge,  one  descending  into  its 
network,  and  the  sixth  projecting  distally  :  the  distal  ray  is  short, 
straight,  and  rounded  off"  at  the  end,  the  other  five  rays  are  much 
longer,  more  or  less  curved,  and  attenuated  to  very  fine  pointed 
extremities.  All  are  minutely  microspined  for  the  whole  or  a 
portion  of  their  length.  The  greatest  breadth  of  the  rays  is 
0-0003". 

In  other  instances  we  find  the  distal  ray  becoming  much 
shorter,  frequently  capitate  (Fig.  16,  Plate  VII.),  and  often  disap- 

*  On  referring  to  Mr.  Carter's  paper  (Joe.  cit.)  I  find  that  his  examination  of 
the  acerate  fusiform  spicules  oi  Dact;jlocalyx  subglobosa  led  him  to  the  same  results. 


128  Transactions  of  the  Society. 

pearing  altogether ;  the  horizontal  rays,  though  sometimes  capitate, 
more  frequently  extending  into  long  sinuous  whip-like  filaments 
(Fig.  14,  Plate  VII.),  which  often  become  branched,  and  thus  give 
rise  to  such  forms  as  that  of  Fig.  8,  Plate  YII.  The  curvilinear 
filaments  of  difierent  spicules  intertwine  with  one  another  in  the 
dermal  surface,  giving  it  a  loosely  woven  texture,  like  a  single  layer 
of  cotton-wool  filaments :  in  some  cases  they  touch  without  uniting, 
in  others  they  are  soldered  together  at  the  point  of  contact. 

The  branched  rays  of  Fig.  8  cannot  be  explained  by  supposing 
secondary  siliceous  fibres  to  have  been  independently  developed  in 
the  dermal  sarcode,  and  subsequently  to  have  become  united  with 
the  spicular  rays ;  these  branched  rays  can  only  be  regarded  as  a 
further  development  of  such  undulating  forms  as  that  of  Fig.  12. 

Another  form  of  sexradiate  is  shown  in  Fig.  18 :  in  this  the 
proximal  ray  has  become  excessively  long,  the  horizontal  arms 
remaining  comparatively  short ;  Figs.  2  and  4  are  similar,  but  in 
the  latter,  one  horizontal  ray  is  bent  backwards  in  an  elongate 
S-like  curve,  and  all  its  rays  are  capitate,  except  the  proximal  one, 
which  is  sharply  pointed.  In  Fig.  18  one  of  the  horizontal  arms 
is  suppressed,  and  in  Fig.  2  the  distal  ray ;  the  number  of  rays 
suppressed  in  difierent  spicules  is  very  variable,  sometimes  both 
proximal  and  distal  rays  disappear,  and  only  the  horizontal  arms 
remain  forming  a  simple  cross.  The  microspining  of  the  spicules  on 
the  other  hand  is  very  constant,  but  the  mode  of  termination  just 
the  opposite,  one,  two,  or  three  rays,  or  any  number  up  to  six 
sometimes  becoming  capitate,  the  proximal  ray,  however,  usually 
remaining  pointed. 

Some  of  the  sexradiate  spicules,  those  for  instance  with  very 
long  proximal  rays  (Fig.  18)  appear  to  accompany  the  bundles  of 
acerates  which  project  beyond  the  dermal  surface,  their  four 
horizontal  arms  not  being  given  ofi"  in  the  dermis,  but  at  some 
distance  outside  it,  after  the  manner  of  anchoring  spicules. 

One  cannot  but  feel  some  curiosity  as  to  the  function  of  these 
various  spicules,  though  without  actual  observation  of  the  habits  of 
the  living  sponge  it  seems  idle  to  speculate  upon  them.  The 
dermal  spicules,  however,  evidently  serve  to  support  the  dermal 
membrane  of  the  sponge ;  the  long  acerates  have  probably,  as 
Bowerbank  would  maintain,  a  "  defensive"  action,  and  it  certainly 
seems  just  possible  that  both  they  and  the  projecting  sexradiates, 
especially  the  latter,  may  serve  to  capture  and  secure  any  minute 
worms  or  other  animals  which  in  wandering  over  the  sponge  should 
come  in  contact  with  their  points.  Nutritious  material  would  be 
freed  from  such  animals  at  every  puncture  on  becoming  wounded, 
and  when  subsequently  decomposition  set  in,  swarms  of  Bacteria 
and  other  organisms  would  result,  and  a  vast  quantity  of  edible 
material  so  be  set  free  to  be  conveyed  by  the  inhalent  currents  into 


On  Badylocalyx  pumieeus  {Stutclihury).    By  W.J.SoUas.    129 

the  interior  of  the  sponge.  A  similar  function  might  perhaps  be 
assigned  to  the  avicularia  of  the  Polyzoa  which  hold  fast  for  a 
long  while  any  little  victim  which  may  have  been  caught  between 
their  beaks. 

First  layer  of  reticulate  skeleton. — Notwithstanding  a  close 
search  was  made  for  them,  no  instances  of  framework  spicules 
existing  in  a  free  state  could  be  found ;  they  could  be  seen  in  the 
very  first  stages  of  cementation,  but  not  earlier:  certainly  the 
dermal  spicules  are  very  distinct,  and  never  become  involved  in  the 
skeletal  network,  unless  by  rare  exception ;  the  acerate  spicules  like- 
wise, though  occasionally  involved,  as  a  general  rule  remain  free. 
In  the  first  stage  of  cementation  we  find  two  or  three  or  more  rays 
of  the  framework  spicules  (Plate  VIII.,  Figs.  1,  3,  and  6)  attached 
to  the  rest  of  the  network,  from  which  the  spicule  seems  to  have 
budded  forth,  the  remaining  rays  projecting  freely  and  usually  out- 
wards towards  the  exterior  of  the  sponge;  these  free  rays  are 
always  more  or  less  clavately  capitate,  and  always  microspined, 
although  they  appear  to  have  already  become  invested  by  a  thin 
layer  of  the  ubiquitous  siliceous  cement.  Some  of  these  rays  are 
very  persistent,  retaining  their  freedom  for  a  long  while,  especially 
those  which  point  directly  towards  the  exterior  of  the  sponge. 
Near  the  centre  of  the  attached  spicule  fine  siliceous  filaments  cross 
from  one  adjacent  ray  to  another,  subtending  the  angle  formed  by 
them,  so  that  when  all  six  rays  have  been  so  connected  together,  a 
hollow  lantern  joint  results,  which,  when  regularly  developed 
(Plate  VII.,  Fig.  11),  closely  resembles  the  octahedral  nodes  of 
Mylinsia  Grayi  or  of  a  Ventriculite.  Usually,  however,  its  form  is 
much  less  symmetrical  than  this,  owing  chiefly  to  irregularities  in 
the  form  and  distribution  of  the  framework  spicules  themselves,  but 
partly  also  to  the  irregular  way  in  which  the  connecting  fibres  join 
them  together. 

The  rays  of  each  spicule  are  bent  in  all  directions,  and  the 
entire  spicules  are  scattered  in  great  confusion,  some  lying  one 
way,  and  some  another.  The  rays  of  adjacent  spicules  thus  exhibit 
no  definite  arrangement  one  with  another  ;  sometimes  the  end  of  one 
touches  the  middle  of  another  ray,  and  where  they  touch  they 
unite ;  sometimes  two  rays  lie  parallel  to  each  other  at  a  slight 
distance  apart,  then  transverse  bridges  of  silica  cross  from  one  to 
the  other,  and  unite  them  into  a  fenestrated  fibre ;  frequently  one 
ray  traverses  the  centre  of  another  spicule,  and  thus  multiplies  the 
number  of  fibres  radiating  from  the  resulting  node  of  the  finished 
network. 

As  the  deposition  of  silica  continues,  the  attached  ends  of  the 
spicular  rays  become  covered  up  and  disappear,  the  fenestra  of  the 
open  fibres  are  filled  in,  and  solid  more  or  less  cylindrical  fibres 
result ;  so,  too,  the  open  lantern  of  the  nodes  is  in  time  obliterated 

VOL.    II.  K 


130  Transactions  of  the  Sodettf. 

and  the  whole  skeleton,  losing  all  traces  of  its  original  composition, 
exhibits  simply  a  reticulation  of  solid  fibres  radiating  from  equally- 
solid  simple  knots.  The  young  fibres  are  at  first  smooth,  but  very- 
early,  almost  as  soon  as  they  become  optically  simple,  they  become 
tubercled,  and  with  age  the  tubercles  increase  in  number  and  size. 

Secondarij  rete. — Aitei  the  formation  of  the  adult  network, 
changes  appear  to  take  place  in  the  distribution  of  the  canals  of  the 
water-system,  by  which  some  of  the  large  meshes  become  no  longer 
needed  as  water-channels,  and  so  are  gradually  filled  up  by  a  second- 
ary network,  of  what  might  appropriately  be  called  "  darning " 
fibres,  from  the  way  in  which  they  seem  to  mend  up  the  gaps  in 
the  aged  skeleton.  In  one  case  I  found  this  secondary  network  in  a 
very  early  stage  (Plate  YIII.,  Fig.  7),  its  component  spicules 
having  only  just  become  soldered  together  by  silica,  and  difiering 
considerably  in  appearance  from  the  budhke  spicules,  or  pullulating 
fibres  of  Bowerbank,  which  likewise  unite  into  a  secondary  network. 
As  the  secondary  fibres  thicken  with  the  continual  deposit  of  silica 
over  them,  they  produce  a  network  of  a  very  difierent  appearance 
to  that  of  the  principal  skeleton,  its  fibres  are  more  rodlike,  often 
sharply  and  conically  spined,  less  thickened  at  the  nodes,  and 
sometimes  more  rectangularly  arranged.  Contrast,  for  example, 
Fig.  7,  which  is  somewhat  like  the  network  of  a  Cypellia  (Zittel), 
or  the  spined  fibre  of  Fig.  6  with  the  excellent  figure  of  the  ordinary 
skeletal  reticulation  given  in  Bowerbank's  Memoir,  plate  i.,  loc.  cit. 

Other  sinctdes  besides  sexradiates  which  become  involved  in  the 
siliceous  fibre. — That  the  large  acerate  spicules  may  sometimes  con- 
tribute to  the  skeletal  network  has  already  been  mentioned,  but  I 
have  never  before  met  with  an  instance  in  which  a  flesh-spicule 
became  eo  involved.  Such  a  case,  however,  is  shown  in  Fig.  1 9, 
Plate  VII.,  where  two  flesh-spicules  are  seen  closely  attached  to  the 
surface  of  a  skeletal  fibre :  in  one  the  process  of  envelopment  has 
not  gone  so  far  as  in  the  other,  so  that,  although  the  angles  between 
its  rays  have  been  to  a  great  extent  filled  up,  yet  its  characteristic 
form  is  more  nearly  retained,  and  the  rays  attached  to  the  fibre  are 
still  so  far  unenveloped  as  to  allow  the  light  to  shine  through 
between  them ;  the  other,  on  the  contrary,  has  become  converted 
into  a  mere  globular  tubercle,  with  the  yet  uncovered  ends  of  its 
rays  projecting  as  little  spines. 

In  commenting  on  the  foregoing  descriptions,  one  may  first 
point  out  the  analogy  which  exists  between  the  rude  folding  of  the 
walls  in  Dactylocalyx  and  the  more  perfect  folding  in  such  extinct 
forms  as  Ccehptychium  and  the  Ventriculites.  The  resemblance 
between  Coeloptychium  and  Dactylocalyx  appears  to  be  especially 
marked ;  in  both  we  have  radial  ridges  and  gullies,  of  about  the 
same  size  in  each ;  in  both  the  ridges  are  bifurcated,  anastomosed 
laterally,  and  marked  on  the  exterior  with  rounded  openings  leading 


On  Dactylocahjx  pumiceus  {Stutchhury).     By  W.J.SolJas.   131 

into  interior  tubes.  In  Coeloptychium,  however,  all  these  features 
possess  a  regularity  which  is  not  to  be  found  in  dactylocalyx ;  the 
ridges  in  the  former  sponge  are  more  uniform  in  size,  straighter  in 
direction,  and  more  regular  in  their  bifurcation  and  anastomosis ; 
the  circular  openings  upon  them  are  also  of  very  uniform  diameter, 
and  are  arranged  at  equal  distances  apart  in  regular  rows. 

Notwithstanding  tliese  difi'erences  of  detail,  however,  an  obvious 
general  resemblance  exists  between  the  two  sponges  when  their 
lower  surfaces  are  alone  compared,  while,  as  regards  general  exter- 
nal form,  one  must  allow  that  Dactylocalyx,  especially  the  variety 
I).  Stutchburyi,  represents  in  a  striking  manner  some  of  the  widely 
infundibuliform  specimens  of  Coeloptychium.  In  other  respects 
more  essential  difi'erences  are  to  be  found. 

The  character  of  the  nodes  in  the  newly  formed  network  of 
Dactylocalyx  may  be  also  alluded  to  again,  since  they  are  always 
hollow  and  reticulate  to  begin  with,  and  not  solid  throughout  as 
in  the  later  stages  of  growth ;  moreover,  as  already  stated,  the 
young  node  often  exhibits  an  octahedral  arrangement  in  its  reticu- 
lation, which  clearly  resembles  that  of  the  true  hollow-jointed 
Hexactinellids,  and  thus  passes  through  a  stage  which  in  the  latter 
sponges  has  become  persistent.  From  this  it  would  appear  that  in 
the  ancestral  form  of  Vitreo-hexactinellid  the  nodes  were  all  cha- 
racterized by  a  lanteru-like  arrangement,  and  that  while  in  some 
of  its  descendants  the  subsequent  deposition  of  silica  at  the  node 
took  place  chiefly  along  the  octahedral  fibres,  and  thus  gave  the 
Yentriculite  knot,  in  others  it  followed  no  definite  direction,  but 
simply  filling  up  the  interspaces,  produced  the  solid  node  of  such 
forms  as  Dactylocalyx. 

Dactylocalyx  pumiceus,  var.  Stutchhiryi  (Plates  V.  and  VI.) — 
This  form  will  not  require  any  lengthy  description,  since  it  agrees 
in  all  important  characters  with  the  preceding,  and  it  is  only  in 
details  of  quite  trifling  value  that  any  difierence  exists.  The  general 
form  is  that  of  a  vase  or  flower-basket,  but  with  a  much  less  ex- 
panded brim  than  the  type  of  D.  piomiceus ;  its  walls  are  also  a 
trifle  thicker  than  the  latter,  and  the  ridges  and  grooves  on  its 
inferior  surface  are  deeper,  narrower,  and  straighter.  The  elliptical 
margin  of  the  cup  measures  1  foot  1  ^  inch  along  the  major  axis, 
and  10  inches  along  the  minor  axis.  It  is  5  inches  in  height.  The 
surface  of  attachment,  i.  e.  the  base  of  the  pedicel  is  covered  with  a 
layer  of  denser  tissue  than  occurs  elsewhere  in  the  sponge.  The 
fibres  of  this  layer  are  usually  flattened,  smooth,  seldom  tuberculated, 
and  only  at  intervals  connected  with  the  interior  body  network. 
Between  such  points  of  connection  the  layer  often  remains  single  in 
thickness,  and  being  flattened  and  smooth  on  both  faces,  presents 
the  appearance  of  a  cribriform  plate  (Plate  VIII.,  Fig.  4).  Some- 
times the  rounded  holes  of  this  plate  are  filled  in  with  a  delicate 

K  2 


132    •  Transactions  of  the  Society. 

tracery  of  secondary  fibres,  when  it  closely  resembles  the  (Plate 
VIII.,  Fig.  5)  dermal  layer  of  some  fossil  sponges.  The  chief  fibres 
of  the  basal  layer  are  formed  on  a  framework  of  sexradiate  spicules, 
which  may  be  revealed  as  casts  by  boiling  in  caustic  potash ;  the 
secondary  fibres  appear  to  originate  in  threads  of  silicifying 
sarcode,  which  have  crossed  from  one  side  of  a  mesh  to  the  other. 
These  secondary  fibres  must  not  be  confused  with  the  secondary 
fibres  of  the  body  skeleton ;  the  latter  spin  across  large  meshes, 
and  are  moulded  on  spicules,  the  former  across  meshes  of  the  small 
fibre,  and  are  not  deposited  on  spicules. 

The  oscules  of  the  inner  surface  of  the  sponge  exhibit  a  tendency 
to  elongate  into  channel-like  grooves,  following  a  radiate  direction 
with  respect  to  the  axis  of  the  vase,  and  soaiewhat  resembling  the 
grooves  of  the  under  surface,  though  of  much  smaller  dimensions, 
never  exceeding,  for  instance,  an  inch  and  a  half  in  length. 

The  openings  of  the  upper  surface  are  so  abundantly  spined  by 
prolongations  of  the  body  skeleton  as  to  give  to  the  whole  interior 
of  the  cup  a  rough  spinose  appearance,  which  is  in  marked  contrast 
to  the  smooth,  even  surface  of  tlie  unspined  fibres  of  the  under  side. 
In  Fig.  2,  Plate  V.,  the  spines  produce  round  the  oscules  the  appear- 
ance of  a  denticulated  mai-gin.  They  may  be  obtained  readily  for 
microscopic  examination  by  breaking  off  with  a  fine-pointed  pair  of 
scissors,  and  catching  them  as  they  fall  on  a  spread-out  sheet  of 
glazed  black  paper.  Three  such  spines  are  represented  in  Figs.  2, 
3,  4,  Plate  VI.  They  consist  of  a  prolongation  of  the  skeletal  net- 
work into  a  generally  hollow  reticulate  and  pyramidal  spine,  which 
might  be  very  appropriately  named  a  "lantern-spine"  from  its 
rough  resemblance  to  the  lanterns  used  in  architecture.  The  longi- 
tudinal fibres  of  the  spine  usually  become  much  thicker  with  age 
than  the  rest,  as  may  be  seen  in  Fig.  2,  where  they  have  entirely 
obscured  the  transverse  fibres  from  sight,  if  transverse  fibres  ever 
existed.  The  subsequent  deposit  of  silica  has,  indeed,  in  many  cases 
so  thickened  the  fibres  and  modified  the  original  reticulate  form  as 
to  lead  one  to  doubt  whether  they  were  ever  modelled  on  a  sex- 
radiate  form.  A  little  boiling  in  caustic  potash,  however,  will  soon 
reveal  the  imbedded  sexradiate  spicules,  which  possess  here  just 
the  same  characters  as  in  other  parts  of  the  network.  The  deposit 
of  silica  over  them  is  so  thiciv,  however,  as  to  overwhelm  them 
altogether  in  some  cases,  as,  for  instance,  in  the  lateral  secondary 
spine  (Fig.  3)  projecting  from  a  principal  one,  which  is  not  repre- 
sented in  the  figure,  but  the  direction  of  which  is  indicated  by  an 
arrow :  in  this  instance  we  have  a  conical  spine  moulded  over  a 
sexradiate  spicule,  and  the  same  thing  has  taken  place  in  the 
pointed  end  of  a  spine  shown  at  Fig.  4.  The  spines  frequently 
support  one  or  more  long  acerate  spicules,  which  pass  through 
and  project  beyond  them  like  a  lance  in  rest.     Now  and  then  these 


On  Baciijlocahjx  immiceus  {Stutclibunj).    By  W.  J.  Sollas.   133 

acerates  become  involved  iu  siliceous  deposit,  and  form  an  integral 
part  of  the  spine. 

Similar  spines  were  detected  on  the  upper  surface  of  the  type 
specimen  of  D.  pumiceus,  but  they  are  much  less  abundant  in  it 
than  in  its  variety  D.  Stutchhuryi. 

Fig.  3.  Fig.  4. 


Fig.  3,  Lateral  spiue.     Fig.  4,  Terminal  point  of  a  "lantern"  spine  x  115. 
The  dotted  lines  indicate  the  ends,  which  have  been  broken  off. 

At  the  bottom  of  the  vasiform  cup  of  D.  Stutchhuryi,  at  one 
side,  is  a  cylindrical  tube  ^  an  inch  in  diameter,  obliquely  perfora- 
ting the  wall  from  side  to  side,  and  in  this,  as  in  a  similar  tube  iu 
D.  immiceus,  remains  of  the  dermal  spicular  layer  were  discovered. 
A  fine  collection  of  the  spicules  was  cut  out,  but,  being  blown  away 
by  a  current  of  air,  was  lost,  and  no  subsequent  searching  succeeded 
in  recovering  it.  Enough  was  obtained  from  what  remained,  how- 
ever, to  show  that  the  characters  of  its  spicules  were  the  same  as 
those  of  the  dermal  layer  already  described,  the  projecting  acerates 
and  dermal  sexradiates  both  being  present ;  a  larger  number  of 
dermal  spicules,  however,  were  found  with  distal  and  proximal  rays 
aborted,  the  four  rays  remaining  being  spread  out  horizontally  in 
the  dermal  surface. 

By  holding  the  sponge  upside  down,  and  smartly  tapping  the 
bottom  of  the  pedicel,  a  large  number  of  long  acerates  were  shaken 
out;  they  were  generally  incomplete  at  one  end,  and  in  a  single 
instance  one  was  observed  with  the  extremity  rounded  off,  thus  pre- 
senting us  with  an  acuate  variety  of  this  kind  of  spicule. 

The  relations  of  the  excurrent  and  incurrent  canals  could  be 
prettily  illustrated  by  holding  the  sponge  up  to  the  light ;  looking 
then  into  the  shaded  interior  of  the  cup,  one  saw  ilkimiuated  patches 
opposite  the  incurrent  openings,  and  these  patches  always  fell  on 
the  continuous  netwoi'k  of  the  sponge,  never  coinciding  with  an 
excurrent  aperture ;  when  the  position  of  the  sponge  was  reversed, 
the  excurrent  apertures  similarly  cast  illuminated  images  on  the 
surface  of  the  outer  ridges,  but  never  coincided  with  incurrent 
openings,  thus  demonstrating  the  absence  of  completely  perforating 
canals.  Of  course  the  perforating  tube  previously  mentioned  is  an 
exception,  but  then  that  does  not  belong  to  the  water-system  of  the 
sponge. 


134  Transactions  of  the  Society. 


XL — Tlie  Aperture  Question.    By  J.  Mayall,  jun.,  F.E.M.S. 

i^Reud  Sth  January,  1879.) 

The  question  of  the  existence  of  apertures,  by  means  of  the  immer- 
sion system,  greater  than  correspond  to  the  maximum  possible  for 
dry  lenses,  has  received  such  powerful  support  in  the  affirmative 
from  Zeiss's  new  oil  lenses,  that  it  is  almost  superfluous  to  call  atten- 
tion to  the  position  of  the  discussion.  But  as  the  chief  exponent  of 
the  adverse  view  still  maintains  that  it  is  an  "  undecided  question," 
I  will  briefly  state  the  most  obvious  points  that  occur  to  me. 

It  had  been  asserted  by  Mr.  Wenham  that  82"  in  the  body  of 
the  front  lens  is  the  limit  beyond  which  no  object-glass  can  collect 
image-forming  rays.  I  quote  a  passage  from  his  writings  to  show 
that  he  has  clearly  pledged  himself  that  this  limit  obtains  equally  in 
dry  and  immersion  lenses  on  balsamed  objects : — 

"  .  .  .  .  the  immersion  lens  ....  had  no  property  for  col- 
lecting from  a  balsam-mounted  object  a  greater  number  of  rays,  but 
that  the  limit  is  the  same  as  in  the  dry  lens." 

Many  passages  might  be  cited  conveying  the  same  view. 

This  is  equivalent  to  asserting  the  existence  of  a  natural  limit, 
depending  on  twice  the  critical  angle  (from  glass  to  air  i,  and,  con- 
sequently, the  impossibility  of  any  objective  collecting  to  a  focus 
a  pencil  of  rays  from  a  radiant  in  balsam  of  greater  aperture  than 
that  which  in  this  medium  corresponds  to  180°  in  air.  It  was  to 
this  assertion  as  regards  the  limit  in  relation  to  immersion  lenses 
that  exception  was  taken. 

On  this  question  Professor  Stokes  was  urged  by  me  to  give  a 
demonstration,  and  I  think  it  must  be  admitted  that  the  assertion  is 
thereby  refuted  as  a  question  of  theory.  Mr.  Wenham  admits  the 
validity  of  the  reasoning,  but  insists  that  in  practical  constructions 
the  limit  of  82°  obtains. 

Mr.  Wenham's  views  had  been  brought  to  definite  issue  by  his 
published  report  of  his  measurement  of  the  aperture  of  Tolles's  i 
immersion  lens  (owned  by  Mr.  Crisp).  The  constructor  had  al- 
leged the  lens  to  be  made  on  a  formula  by  which  an  aperture  was 
obtained,  measured  in  the  body  of  the  front  lens  (or  in  a  suitably 
adjusted  semi-cylinder — for  it  is  demonstrable  that  the  results  are 
equivalent),  16°  beyond  the  maximum  possible  for  dry  lenses, — that 
is  to  say,  Mr.  Tolles  claimed  for  it  an  aperture  in  glass  of  98°. 

Mr.  Wenham  reported  the  aperture  to  be  68°  in  glass. 

The  point  of  interest  to  me  was  to  prove  whether  the  aperture 
exceeded  82°. 

Passing  over  some  discussions  that  took  place  in  correspondence, 
•which  were  not  communications  to  the  Society,  I  may  state  that  I 
felt  under  an  obligation  to  place  before  the  Society  the  evidence  I 


The  Aperture  Question.     Bij  J.  May  all,  jun.  135 

could  adduce  on  behalf  of  the  original  claim  that  the  aperture  of 
the  I  exceeded  82', — the  evidence  being  Professor  Keith's  com- 
putation of  the  angle,  and  the  actual  measurement  by  means  of 
Professor  Abbe's  apertometer  which  I  exhibited  at  the  meeting  in 
June  last. 

Mr.  Wenham's  answer  to  the  computation  amounts  to  this : — 
Because  the  computed  angle  is  based  on  the  assumption  that  the 
radiant  is  in  balsam,  therefore  it  falls  to  the  ground. 

Now  the  question  with  regard  to  this  lens  never  was  to  know 
if  the  aperture  in  the  body  of  the  front  lens  could  exceed  82°  when 
adjusted  so  as  to  have  a  front-focus  in  air.  No  one  had  ever  alleged 
such  a  proposition.  All  admit  that  82^  (in  glass)  is  the  limit  for 
dry  lenses,  and,  of  course,  all  lenses  may  be  regarded  as  dry  if  there 
be  a  stratum  of  air  between  the  object  and  the  front  lens.  The 
question  was,  What  is  the  aperture  when  the  lens  is  adjusted  to  have 
a  front-focus  in  balsam?  To  this  Professor  Keith's  computation 
answers  by  tracing  the  paths  of  different  rays  from  the  back-focus 
to  the  front-focus  in  balsam,  and  the  result  (110°)  proves  that  the 
formula  is  designed  to  produce  an  aperture  greater  than  corresponds 
to  180^  in  air, — which  was  to  be  demonstrated.  Mr.  Wenham's 
criticism  upon  it  is  thus  seen  to  be  irrelevant. 

When  the  radiant  is  in  balsam,  and  in  immersion  contact  with 
the  front  lens,  the  critical  angle  (between  glass  and  air)  is  no  longer 
a  factor  in  the  elements,  and  can  have  nothing  to  do  with  the  aper- 
ture, because  the  rays  do  not  go  into  air  until  their  emergence  at 
the  second  surface  of  the  front  lens,  which  is  not  parallel  to  the 
plane  front,  but  deeply  curved.  With  a  dry  lens,  the  effective  angle 
of  rays  from  the  object  in  balsam  is  limited  at  the  object  itself  to 
82^ — no  greater  pencil  can  emerge  from  the  cover-glass.  With  an 
immersion  lens  this  limit  varies  with  the  immersion  medium ;  with 
water  it  is  about  126°,  with  oil  the  limit  depends  on  the  construc- 
tion of  the  lens,  and  may  possibly  be  carried  as  near  to  180°  in 
glass  as  the  present  dry  lenses  approach  their  limit  of  82°.  This  is 
a  matter  for  the  ingenuity  of  the  opticians. 

With  regard  to  the  elements  furnished  for  the  computation,  it  is 
extremely  improbable  that  Mr.  ToUes  arrived  at  the  precise  nume- 
rical data  by  mere  guessing ;  but  even  in  that  case,  as  formerly  re- 
marked by  Professor  Keith,  "  the  force  of  the  result  would  have 
been  the  same." 

In  confutation  of  Mr.  Wenham's  position  in  the  aperture  ques- 
tion, we  have  had  two  formulae  for  immersions  placed  before  us,  by 
which  an  aperture  in  the  body  of  the  front  lens  exceeding  the  limit 
of  dry  objectives  has  been  traced  to  the  radiant  in  balsam :  the  one 
relating  to  the  yV  (three  system)  by  Tolles  in  the  collection  of  the 
United  States  Army  Medical  Museum ;  the  other,  to  the  \  (four 
system)  referred  to  above ;  in  each  of  which  Professor  Keith  has 


136  Transactions  of  the  Society. 

computed  the  aperture  to  be  about  1 1 0^.  We  have  Professor  Stokes's 
authority  for  the  vahdity  of  these  computations. 

As  to  practical  measurements :  we  have  the  testimony  and  report 
of  Dr.  Woodward,  Professor  S.  Newcomb,  and  Professor  Keith  on 
behalf  of  a  four  system  3^  by  Tolles.  We  have  Dr.  Woodward's  re- 
port of  the  measurement  of  the  xV  to  which  the  earlier  computation 
referred;  and  I  exhibited  the  measurement  of  the  \  before  the 
Society,  with  Professor  Abbe's  apertometer.  In  all  these  cases  aper- 
tures were  recorded  beyond  the  limit  contended  for  by  Mr.  Wenham. 

I  felt  bound  to  exhibit  the  actual  measurement  of  the  \  to  which 
the  newer  computation  referred ;  at  the  same  time  I  was  provided 
with  twelve  other  immersion  lenses  by  Tolles,  Powell  and  Lealand, 
and  Zeiss,  all  of  which  would  have  afforded  similar  proof. 

I  do  not  attempt  to  follow  Mr.  Wenham  in  his  various  sug- 
gestions for  angle  measuring.  I  have  found  the  results  obtained 
with  Professor  Abbe's  apertometer  confirmed  by  a  modification  of 
Professor  Eobinson's  plan  of  measuring  (adapted  for  immersion 
lenses),  and  therefore,  until  Mr.  Wenham  can  show  some  material 
error  likely  to  arise  from  the  proper  use  of  the  apertometer,  I  shall 
continue  to  regard  it  as  a  convenient  and  reliable  appliance. 

With  regard  to  the  supposed  effect  of  the  "  outer  oblique  rays 
extending  to  the  margin  of  the  field,"  Professor  Keith's  computa- 
tions refer  only  to  the  central  pencil — have  nothing  to  do  with  any 
appreciable  diameter  of  field.  If  apertures  be  measured  by  means 
of  a  small  pencil  of  sunlight  from  the  eye-piece,  the  diameter  of  the 
field  at  the  front  focus  is  almost  inappreciable,  and  therefore  no 
question  can  possibly  arise  concerning  "  outer  oblique  rays  " :  this 
has  been  done  in  many  cases  to  test  the  accuracy  of  the  aperto- 
meter method. 


(    137    ) 
NOTES  AND  MEMOEANDA. 


Cells,  and  their  Vital  Phenomena.— Professor  W.  Flemming,  of 
Kiel,  has  published  *  a  detailed  account  of  his  extensive  researches  on 
the  structure  of  nuclei,  and  their  behaviour  during  the  process  of  cell- 
division.  The  observations  were  made  chiefly  on  cells  from  various 
parts  of  the  body  of  the  larval  Salamandra  ;  these  were  examined  in 
the  living  state,  and  also  after  treatment  with  chromic  acid,  followed  by 
absolute  alcohol,  staining  with  safranin,  and  clarifying,  after  a  second 
treatment  with  absolute  alcohol,  with  oil  of  cloves.  H^ematoxylin 
staining  of  chromic  and  picric  acid  preparations  was  also  employed. 
According  to  Flemming,  the  quiescent  nucleus  consists  of — 

1.  An  investing  membrane. 

2.  An  intranuclear  network  consisting  of  an  extensive  system  of 
ramified  filaments  exhibiting  at  intervals  thickenings  or  pseudo- 
nucleoli.f 

3.  The  true  nucleoli. 

4.  A  pale  ground-substance  filling  up  the  remaining  space,  and 
devoid  of  visible  structure  in  the  living  state,  but  assuming  a  granular 
or  fibrillar  appearance  by  the  action  of  reagents. 

In  the  process  of  cell-division  the  nucleus  passes  through  the 
following  phases : — 

1.  The  somewhat  coarse  intranuclear  network  is  converted  into  a 
fine-meshed  coil,  presenting  a  basket-like  appearance. 

2.  The  meshes  of  the  coil  become  coarser  and  at  the  same  time 
looser. 

3.  The  coil  assumes  a  wreath-like  form,  a  space  being  left  in  the 
centre  of  the  nucleus  free  from  filaments. 

4.  The  filaments  again  advance  to  the  centre,  but  separate  into 
loops  peripherally  so  as  to  give  the  whole  nucleus  a  star-like  form. 

5.  The  individual  rays  of  this  star  imdergo  longitudinal  fission 
along  their  whole  length,  producing 

6.  Another  star-form,  distinguished  from  the  first  by  the  extreme 
fineness  of  its  rays. 

7.  The  star-form  disappears,  its  filaments  becoming  collected  into 
a  plate-like  body,  situated  equatorially  across  the  centre  of  the  cell. 

The  foregoing  are  the  changes  undergone  by  the  mother-nucleus 
preparatory  to  division  ;  the  following  are  the  stages  of  the  daughter- 
nuclei.  It  will  be  seen  that  they  correspond  with  those  of  the  mother- 
nucleus,  but  occur  in  an  inverse  order. 

8.  The  equatorial  plate  assumes  a  sort  of  barrel-shape ;  a  plane 
across  the  equator  of  the  barrel  is  free  from  filaments,  and  marks  the 
plane  of  division  of  the  nucleus ;  from  this  plane  the  filaments 
radiate,  converging  slightly,  in  two  directions,  or  towards  the  original 
bounding  planes  of  the  equatorial  plate. 

9.  Probably,  though  this  is  by  no  means  certain,  the  filaments 

*  '  Archiv  f.  Mikr.  Anat.,'  vol.  xvi.  (1878)  p.  302. 

t  This  word  la  employed  in  a  different  sense  by  Van  Beneden. 


138  NOTES  AND   MEMOEANDA. 

now  fuse  together  in  pairs,  producing  a  similar  figure  to  the  last,  but 
coarser. 

10.  The  two  daughter-nuclei  (the  two  halves  of  the  barrel-form) 
separate  from  one  another,  and  each  assumes  a  star-shape. 

11.  The  rays  of  each  star  unite  and  form  loops,  the  wreath-form 
being  the  result. 

12.  The  filaments  of  the  wreath  become  thicker  and  more  closely 
meshed. 

13.  As  the  process  of  division  approaches  completion,  the  coils 
become  finer,  and  the  basket-form  is  produced. 

14.  Finally,  the  ordinary  intranucleolar  network  is  produced, 
marking  the  completion  of  the  division  process  and  the  entrance  of 
the  nuclei  into  a  state  of  quiescence. 

Picro-carmine  for  Cell-nuclei. — In  the  Eeport  published  last 
August  of  the  Proceedings  of  the  International  Congress  of  Botanists, 
held  at  Amsterdam  in  1877,  is  a  paper  by  M.  Treub,  who  drew 
attention  to  the  use  of  picro-carmine  as  a  reagent  for  this  purpose. 
His  first  step  is  to  kill  the  cells  by  absolute  alcohol,  according  to  the 
directions  of  Strasburger.  After  making  some  sections  of  tissues 
which  had  remained  in  the  liquid,  the  prejiarations  are  placed  in  a 
1  per  cent,  solution  of  picro-carmine,  for  a  time  varying  from  four  to 
twenty  hours ;  they  are  then  shaken  in  distilled  water  in  order  to 
dissolve  the  picric  acid,  and  are  placed  in  a  mixture  of  glycerine  and 
distilled  water,  which  is  gradually  replaced  by  pure  glycerine  con- 
taining 1  per  cent,  of  formic  acid.  After  this  treatment  the  nuclei 
almost  always  assume  a  fine  red  colour,  whilst  the  protoplasm  remains 
entirely  uncoloured,  which  enables  the  slightest  changes  which  take 
place  in  the  nuclei  to  be  at  once  distinguished.* 

Influence  of  the  different  Colours  of  the  Spectrum  on  Animals 
and  Plants.  —  1.  Animals. — Observations  on  the  influence  of  the 
different  coloured  rays  of  solar  light  upon  the  nutrition  of  plants 
have  been  more  numerous  than  those  on  the  development  of  animals. 
M.  Beclard  in  1858  experimented  with  eggs  of  Musca  carnaria  under 
different  coloured  glasses,  and  found  that  the  eggs  developed  very 
unequally,  those  of  the  violet  and  blue  rays  developing  most  rapidly, 
and  in  the  green  least. 

M.  E.  Yung  t  has  for  three  years  experimented  at  the  University 
of  Geneva  with  the  eggs  of  Bana  temporaria,  JR.  esculenta,  Salmo 
trutta,  and  Lymnea  stagnalis. 

The  eggs  were  placed  directly  after  fecundation  in  vessels  which 
were  plunged  in  solutions  coloured  respectively  violet,  blue,  green, 
red,  and  white,  one  being  also  placed  in  the  dark. 

The  general  results  were  as  follows : — 

(1)  The  different  coloured  rays  of  solar  light  act  in  a  very 
different  manner  on  the  development  of  the  eggs  of  the  above 
animals. 

(2)  Violet  light  quickens  the  development  in  a  very  remarkable 

*  'Bull.  Soc.  Bot.  de  France,'  vol.  xxv.  (1878)  p.  129. 
t  'Comptes  Reiidus,'  vol.  Ixxxvii.  (1878)  p.  998. 


NOTES  AND   MEMORANDA.  139 

manner.     Blue  comes  next,  and  then  yellow  and  white,  which  are 
nearly  equal  in  their  effects. 

(3)  Darkness  does  not  prevent  development,  but,  contrary  to  the 
results  of  MM.  Higginbottom  and  MacDonnell,  does  retard  it. 

(4)  Eed  and  green  light  seem  to  be  hurtful,  as  the  complete 
development  of  the  eggs  placed  in  these  colours  could  not  be 
obtained. 

(5)  Tadpoles  subjected  to  the  same  conditions  and  deprived  of 
food  died  sensibly  sooner  in  violet  and  blue  light  than  in  the  others — 
they  consumed  their  food  store  more  rapidly. 

(6)  The  mortality  seemed  to  be  greater  in  coloured  light  than  in 
white  light.  Nevertheless,  as  the  results  have  not  always  agreed  on 
this  point,  it  would  be  premature  to  consider  this  as  positively 
proved. 

2.  Plants. — In  1869  M.  P.  Bert  showed  *  that  certain  plants  placed 
under  green  glass  soon  died.  He  thought  the  explanation  was  to  be 
found  in  the  green  colour  of  the  leaves — to  allow  none  but  gi-een  light 
to  reach  them  was  to  give  them  what  they  rejected  as  useless.  Eeflect- 
ing  that  these  leaves,  under  a  great  thickness,  appeared  red,  he 
thought  the  plants  would  die  also  behind  red  glass,  but  was  surjirised 
to  see  that  they  did  not. 

This  apparent  contradiction  led  him  to  undertake  a  fm-ther  ex- 
amination.! 

If  green  and  red  glasses  are  examined  through  the  spectroscope 
by  diflfused  sunlight,  we  see  that  the  red  glass  intercepts  the  yellow 
and  all  the  most  refrangible  part  of  the  spectrum,  only  allowing  the 
orange  and  the  red  to  pass ;  while  the  green  glass  intercepts  about 
three-quarters  of  the  red,  starting  from  the  left  hand. 

The  first  maintains  life,  the  second  kills,  and  therefore  the 
necessary  part  of  the  spectrum  is  found  in  this  red  which  the  green 
glass  absorbs. 

To  further  determine  whether  this  property  is  to  be  attributed  to 
the  whole  intercepted  extent  of  the  red,  he  compared  a  solution  of 
chlorophyll,  with  the  gi'een  glass,  and  saw  that  the  part  of  the  red  which 
it  absorbed,  extended,  from  left  to  right,  as  far  as  the  first  absorption 
band  characteristic  of  chlorophyll  (included  between  the  lines  B  and 
C),  and  concluded  that  it  was  the  part  of  the  spectrum  corresponding 
to  this  band,  which,  absorbed  by  the  leaf,  was  indispensable  to  its 
life. 

Further  experimenting,  he  found  that  plants,  lighted  by  a  good 
diflfused  light,  and  surrounded  with  vessels  with  parallel  glass  sides 
containing  an  alcoholic  solution  of  chlorophyll  very  frequently 
renewed,  immediately  ceased  growing,  and  very  soon  died :  this 
solution,  which  was  very  weak  and  in  a  very  thin  layer,  intercepted 
hardly  any  but  the  characteristic  parts  of  the  red. 

The  indispensable  part  of  white  light  is  consequently  there,  where, 
moreover,  M.  Timiriazeff  J  has  recently  found  the  maximum  of  re- 

*  '  Comptes  Rendus,'  14tli  February,  1870. 
t  Ibid.,  vol.  Ixxxvii.  (187S)  p.  695. 
i  Ibid.    Sitting  of  28th  May,  1877. 


140  NOTES    AND    MEMORANDA. 

duction  of  carbonic  acid.      If  we  prevent  it  from  reaching  tlieleaf,  • 
the  plant  being  reduced  to  consume  the  reserves  previously  accumu- 
lated, becomes  exhausted,  and  iinally  dies. 

But  though  this  part  of  the  spectrum  is  necessary  to  plant  life,  it 
cannot  be  said  that  it  is  sufficient.  Behind  red  glass,  plants  live  a 
very  long  time,  no  doubt,  but  they  become  elongated  to  excess,  and 
slender,  with  their  leaves  narrow  and  pale-coloured,  because  they  are 
deprived  of  the  violet  blue  rays. 

Thus  every  part  of  the  solar  sijectrum  contains  portions  which 
play  an  active  role  in  the  life  of  plants.  In  the  most  refrangible  rays 
are  found  those  which  govern  the  destruction  of  tension.  In  the  red 
are  those  which  determine  the  tension  of  the  tissues  and  produce  the 
phenomena  of  reduction,  which  are  the  foundation  of  vegetable  life. 
Their  total,  properly  proportioned  in  white  light,  is  necessary  for 
the  vital  harmony. 

It  is  very  probable  that  these  parts  utilizable  by  plants  are 
accurately  marked  by  the  difiFerent  absorption  bands  of  chlorophyll ; 
but  to  be  quite  sure,  we  should  have  to  experiment  with  luminous 
spectra,  intercepting  the  different  parts  by  screens,  and  recomposing 
by  means  of  lenses.  The  bad  weather  last  summer  did  not  allow 
M.  Bert  to  operate  with  the  solar  spectrum,  and  he  accordingly  made 
arrangements  for  using  a  strong  electric  light,  the  results  of  which 
have  not  yet  been  published. 

Colonel  Woodward  on  the  Oil- Immersion  Objectives  and  the 
Apertometer. — Colonel  Woodward  has  examined  the  i  and  -^^  objec- 
tives made  by  Mr.  Zeiss,  on  what  Professor  Abbe  terms  the  "  Stej^hen- 
son  homogeneous  immersion  system,"  and  thus  reports  upon  them  : — 

"  My  first  trial  by  lamplight  immediately  convinced  me  of  the 
excellent  quality  of  the  |^  and  of  the  surpassing  excellence  of  the  -^^. 
On  testing  them  by  monochromatic  sunlight,  using  a  microscope 
body  with  draw-tube,  by  which  I  could  get  ten  inches  precisely 
with  a  range  of  a  couple  of  inches  either  way,  I  speedily  satisfied 
myself  that  the  performance  of  the  ^  fully  equalled,  while  the  ^  ex- 
celled, the  best  of  the  large  collection  of  immersion  objectives  belong- 
ing to  the  Museum.  For  photographic  purposes  the  objectives  gave 
similarly  satisfactory  results. 

I  find  that  the  saving  of  time  in  using  these  oil-immersion 
objectives  on  histological  preparations  mounted  in  balsam,  and  in  all 
similar  work,  is  very  great.  With  water  and  even  glycerine  immer- 
sion objectives  every  conscientious  worker  loses  much  time  with  the 
cover  adjustment,  and  this  is  entirely  economized,  while  the  results, 
instead  of  being  inferior,  are  superior  to  any  obtainable  with  the  best 
objectives  made  on  any  other  principle." 

Colonel  Woodward's  measurement  (by  a  method  of  his  own)  of  the 
aperture  of  the  objectives  gave  115°  interior  angle  for  the  ^  and  114° 
for  the  ^.  By  the  apertometer  he  made  the  angle  of  each  a  little 
more  than  1  •  25  (numerical  aperture).  In  regard  to  the  scale  of  the 
apertometer.  Colonel  Woodward  considers  that  it  has,  among  other 
inconveniences,  this,  that  its  divisions  are  too  far  apart  for  any  very 


NOTES   AND    MEMORANDA.  141 

accurate  readings,  and  that  it  is  to  be  regretted  that  it  was  not 
arranged  so  as  to  read  the  angle  in  crown  glass  (i.  e.  the  interior 
angle)  to  degrees.  It  would  have  been  far  more  convenient  for 
ordinary  use,  and  just  as  easy  to  compute  water,  air,  or  glycerine 
angles  from  the  crown-glass  angles  as  from  the  ordinary  scale. 

Professor  Abbe,  writing  to  Mr.  Stephenson,  says  that  "for  the 
observation  of  bacteria  the  oil-immersion  lenses  are  becoming  more 
and  more  appreciated  by  German  microscopists.  There  is  no  doubt 
your  plan  which  enabled  us  to  get  rid  of  the  refractions  outside  the 
objective  and  at  the  front  face,  will  be  considered  an  important  step 
in  the  improvement  of  objectives.  In  addition  to  the  increase  of 
aperture,  the  homogeneity  of  the  medium  from  the  object  to  the  first 
spherical  surface  turns  out  to  be  a  great  advantage  in  respect  to  fine 
definitions." 

Diffraction  Experiments  with  Plenrosigma  angulatum. — Colonel 
Woodward  also  says,  in  reference  to  these  experiments,*  that  though 
by  lamplight  he  readily  observed  all  the  phenomena  as  described  by 
Professor  Abbe,  yet  on  trying  by  sunlight  he  obtained  dificrent  results. 
The  fine  longitudinal  lines  produced  by  diffraction  were  distinctly 
visible  on  all  parts  of  all  the  frustules  and  entirely  without  limita- 
tion to  the  adherent  parts  as  required  by  Professor  Abbe's  theoretical 
explanation.  In  the  photographs  of  a  frustule  in  which  the  adherent 
parts  are  comjjaratively  small  (laid  before  the  Society  at  the  February 
meeting),  that  obtained  with  the  i  showed  the  diffraction  lines,  after 
the  introduction  of  the  diaphragm,  on  all  parts  of  the  frustule  without 
regard  to  the  line  of  adhesion,  while  with  the  one  taken  with  the  jV, 
the  same  was  true  for  one  side  of  the  frustule,  the  other  side  being 
slightly  out  of  focus.  A  similar  diffi-action  picture  of  the  right  side 
of  the  frustule  could  have  been  obtained,  but  then  the  left  would  have 
been  out  of  focus,  a  result  of  the  form  of  the  frustule.  In  neither 
case  are  the  diiraction  lines  limited  to  the  adherent  parts.  When, 
however,  the  illumination  was  obtained  by  lamplight  the  diffraction 
lines  were  rigidly  limited  to  the  adherent  parts. 

On  these  remarks  Professor  Abbe  writes  as  follows : — 
"  The  fact  observed  by  Colonel  Woodward  that  the  longitudinal 
lines  on  Angulatum  appear  throughout  the  whole  frustule  in  observing 
or  photographing  with  direct  sunlight,  is  not  astonishing  to  me  after 
having  considered  the  distance  of  those  lines  more  accurately  than  I 
had  done  before.  The  photographs  give  this  distance  (measured  in 
the  middle  part  of  both  photographs)  =0"335/x(fc  =  0* 001  mm.  = 
1  micro-millimetre),  the  wave-length  of  D  =  0*589 /a,  F  =  0'46/a. 
Therefore  the  distance  exceeds  the  half  wave-length  even  of  D,  and 
the  lines  are,  theoretically,  within  the  range  of  the  numerical  aperture 
1  •  0  for  oblique  light.  It  will  thus  be  a  matter  of  intensity  of  illu- 
mination only,  whether  they  will  be  visible  or  not  visible  through  a 
film  of  air,  and  it  is  quite  natural  that  on  the  non-adhering  parts  of  a 
valve  they  are  not  visible  with  lamj)light,  but  yet  are  visible  by 
direct  sunlight." 

*  This  Journal,  vul.  i.  p.  53. 


142  NOTES   AND   MEMORANDA. 

Brain  of  Invertebrates. — M.  Dietl  has  two  important  papers 
on  this  subject  in  the  '  Proceedings  of  the  Vienna  Academy,'  *  in  the 
first  of  which  he  describes  the  brains  of  Eledone,  Sepiola,  and  Tethys, 
and  in  the  second  that  of  Astacus  and  Squilla.  The  former  is  illus- 
trated by  nine  plates,  the  second  by  one  plate.  The  papers  consist 
entirely  of  detailed  descriptions  of  the  brains  in  question,  and  do  not 
readily  admit  of  abstracting.  We  are  therefore  reluctantly  obliged 
to  confine  ourselves  to  the  record  of  their  publication. 

Poison  Apparatus  and  Anal  Glands  of  Ants. — Dr.  August  Forel 
gives  in  the  '  Zeitsch.  fiir  wiss.  Zoologie  '  f  an  exhaustive  account,  with 
two  plates,  of  these  structures.  He  first  gives  an  account  of  the  sting 
in  the  Formicidce,  stating  that  in  his  Section  a  of  that  family  the 
organ  is  quite  rudimentary,  while  in  Section  /3,  although  very  small 
and  delicate,  it  has  all  the  structure  of  the  sting  of  Myrmicidce  and 
Pone7-idce. 

Of  the  poison  apparatus,  consisting  of  gland  and  receptacle,  there 
are  two  types,  one  found  in  Section  a  of  Formicidce,  the  other  in 
Section  /3  of  that  family  and  in  all  other  ants.  From  this  circum- 
stance, as  well  as  from  the  structure  of  the  sting,  Forel  proposes  to 
divide  Formicidce.  into  two  sub-families,  Camponotidce  (Section  a),  and 
Bolichoderidce  (Section  /3).  The  types  are  distinguished  as  (1)  poison- 
bladder  with  pad  {Polster) ;  and  (2)  poison-bladder  with  knob 
{Knopf). 

(1.)  In  the  first  type  the  poison-bladder  is  elongated  and  widened 
and  provided  with  a  duct  of  but  little  less  diameter  than  itself.  Its  walls 
consist  of  a  tunica  intima  bounding  its  cavity,  then  of  a  layer  of  pro- 
toplasm with  scattered  nuclei,  representing  an  epithelium,  and  finally 
of  an  outer  tunica  propria  containing  muscular  fibres.  On  its  dorsal 
side,  between  the  intima  and  j^ropria,  is  a  large  flattened  cushion- 
like body,  the  pad,  consisting  of  a  greatly  coiled,  branched  or  un- 
branched  chitinous  tube,  the  coils  being  separated  from  one  another  by 
a  layer  of  nucleated  protoplasm.  Although  the  pad  itself  is  not 
more  than  2  mm.  long,  the  tube  may  attain  a  length  of  20  mm.  At 
one  end  the  tube  opens  into  the  bladder,  with  the  intima  of  which 
the  edges  of  the  aperture  are  continuous.  At  the  other  end,  situated 
posteriorly  or  xmder  the  duct  of  the  bladder,  it  is  connected  with  a 
pair  of  glandular  filaments,  lying  external  to  and  on  the  dorsal  side  of 
the  bladder.  These  filaments  are  the  free  portion  of  the  poison- 
gland,  the  coiled  tube  of  the  pad  with  its  protoplasm  constituting  its 
intra-vesicular  portion.  The  free  gland-cpeca  consist  of  a  layer  of 
epithelial  cells,  covered  by  a  tunica  propria  continuous  with  that  of 
the  bladder,  and  lined  by  an  intima,  bounding  the  lumen,  and  sending 
off  very  fine  lateral  tubes  to  the  individual  gland-cells. 

(2.)  In  the  second  type  the  poison-bladder  is  small  and  nearly 
globular,  and  its  duct  is  a  fine  tube  with  walls  thrown  into  trans- 
verse folds.  The  free  portions  of  the  poison-gland  are  shorter  and 
thicker  than  in  the  first  type ;  the  united  portion,  answering  to  the 

*  '  Sitzungsberichte  der  (Wiener)  k.  Akad.  der  Wiss.,'  vol.  Ixxvii.    (1878), 
1st  Alith.  p.  481. 

t  '  Zeitsch.  f.  wiss.  Zool.,'  vol.  xxx.  (Suppl.),  (1878),  p.  28. 


NOTES   AND  MEMORANDA.  143 

pad  of  Camponotidce,  pierces  tte  tunica  propria  of  the  bladder,  losing 
its  own  tunica  propria,  and,  pushing  the  intima  before  it,  hangs  free 
in  the  cavity,  either  as  a  twisted  tube  with  a  knob  at  the  end — 
whence  the  name  of  this  type  of  apparatus — or  as  a  mere  knob :  in 
either  case  the  whole  intra-vesicular  portion  of  the  gland  is  invested 
by  the  invaginated  intima  of  the  bladder,  which  takes  the  place 
of  the  tunica  propria.  At  the  extremity  of  the  knob  is  the 
aperture  by  which  the  gland  opens  into  the  bladder,  and  at  which  the 
in-turned  intima  of  the  latter  becomes  continuous  with  the  true 
intima  of  the  gland.  The  protoplasm  of  the  gland  exhibits  no  cell 
contours,  but  only  nuclei  imbedded  in  granular  protoplasm,  the  latter 
being  pierced  by  the  fine  chitinous  offshoots  of  the  intima  of  the 
gland.  The  knob  is  made  of  an  accumulation  of  cells,  also  with 
chitinous  tubules. 

In  connection  with  both  types  of  poison  apparatus  are  found 
accessory  glands  (Nehendrusen)  lying  towards  the  ventral  side  of  the 
poison-bladder,  and  answering  to  the  oil-gland  of  bees  and  other 
Hymenoptera.  They  are  unpaired  glands,  opening  by  a  duct  imme- 
diately below  the  opening  of  the  poison-bladder,  and  may  be  either 
simple  or  bilobed.  The  wall  consists  of  five  layers,  an  intima 
bounding  the  large  cavity,  a  layer  of  polygonal  epithelial  cells,  one  of 
scattered  nuclei,  a  tjmica  propria,  and  a  network  of  fine  muscular 
fibres.     The  secretion  is  oily  and  of  a  yellowish  colour. 

The  anal  glands  and  anal  bladders  are  stated  to  have  been 
hitherto  overlooked  in  ants ;  they  are  formed  by  an  infolding  of  the 
wall  of  the  cloaca  between  the  anus  and  the  pygidium  or  last  out- 
wardly visible  tergum.  The  bladders  are  two  large  ovoidal  sacs  closely 
applied  to  one  another  in  the  middle  line,  and  uniting  posteriorly 
into  a  small  ampulla  from  which  proceeds  the  short  duct ;  their  walls 
consist  of  an  intima,  a  delicate  protoplasmic  matrix  with  scattered 
nuclei,  a  tunica  propria,  and  a  network  of  muscles.  The  glands  are 
also  two  in  nvimber,  and  each  is  closely  applied  to  the  outer  wall  of 
the  corresponding  bladder,  into  which  its  duct  opens  by  a  large 
funnel-shaped  aperture.  The  gland-cells  are  large  and  spherical, 
and  very  easily  separated  from  one  another ;  each  contains  a  large 
nucleus  with  many  nucleoli,  and  is  suji plied  with  a  special  tracheal 
branch.  The  duct  of  the  gland  gives  off  fine  lateral  offshoots,  one  of 
which  proceeds  to  each  gland-cell :  on  reaching  the  cell  its  protoplasmic 
outer  layer  becomes  continuous  with  the  cell-membrane,  while  its 
chitinous  intima  pierces  the  j)rotoplasm  of  the  cell,  increasing  in 
diameter,  and  describes  several  curves,  probably  ending  blindly. 
Forel  ascribes  the  peculiar  smell  of  some  ants  (e.  g.  Tapinoma)  to  the 
secretion  of  these  anal  glands  :   he  has  seen  it  ejected  on  an  enemy. 

Parthenogenesis  in  Bees. — In  continuation  of  the  discussion  on 
this  subject  (see  p.  88),  M.  M.  Giard  *  considers  that  the  true  explanation 
of  the  observation  of  M.  Perez  is  to  be  found  in  a  supplementary  means 
of  nature  to  assm-e  the  reproduction  of  the  immense  posterity  of  the 
social  Hymenoptera.  Besides  the  normal  queens,  which  lay  continually, 

*  '  Comptes  Reudus,'  vol.  Ixxxvii.  (1878)  p.  755. 


144  NOTES  AND   MEMORANDA. 

there  are  fertile  workers,  among  which  copulation  is  not  observable, 
and  is  perhaps  even  impossible  for  various  reasons.  They  are  well 
proved  and  frequent  amongst  the  wasps  and  Polistes  ;  to  them  is  attri- 
buted, among  the  drones,  the  considerable  number  of  males  which  are 
observed  late  in  the  autumn.  They  exist  among  certain  species  of  ants, 
notably  Formica  sanguinea.  Fertile  workers  have  been  recognized 
for  a  long  time  among  bees ;  but  until  recently  these  fertile  workers, 
as  t:  ey  only  laid  male  eggs,  like  the  drone-bearing  queens,  conform- 
ably to  the  Dzierzon  theory,  were  thought  to  be  very  rare  and 
accidental.  They  are,  on  the  contrary,  frequent,  and  coexist  with 
the  queen  in  a  great  number  of  hives.  As  in  M.  Perez's  hive  there 
was  a  mixture  of  yellow,  black,  and  hybrid  workers,  the  fertility  of 
certain  workers  of  the  two  last  sorts  is  sufficient  to  explain  the  mix- 
ture. An  exclusive  laying  of  black  drones  has  even  been  found  in  the 
case  of  an  analogous  hive.*  More  than  this,  a  yellow  Italian  mother, 
fecundated,  not  by  a  black  male,  but  by  a  yellow  Italian  male  of  her 
own  race,  being  given,  by  artificial  swarming,  to  an  orphan  colony  of 
black  bees,  not  only  numeroits  yellow  but  also  black  drones  appeared 
after  a  certain  time.  These  latter,  M.  Giard  thinks,  could  only  come 
from  fertile  black  workers ;  "  for,  in  order  to  find  the  black  ancestors 
of  M.  Sanson,  it  would  be  necessary  to  throw  back  the  atavism  into 
the  night  of  ages,  farther  perhaps  than  the  bees  of  Virgil."  To  decide 
this  question  irrefutably,  we  must  employ  the  method  of  elimination, 
and  suitably  separate  the  layings  of  the  queen  and  of  the  fertile 
workers. 

Hermaphroditism  in  Perlidse. — Dr.  Alexander  Brandt,  of  St. 
Petersburg,  describes "f"  an  interesting  case  of  hermaphroditism  in 
certain  of  these  orthopterous  insects  (Perla  hipunctata,  &c.),  in  which 
he  found  undoubted  ovaries  in  connection  with  the  testes  of  male 
larvae,  both  male  and  female  glandular  f  Hides  being  developed  as 
out-pushings  of  one  and  the  same  excretory  duct. 

Employment  of  Mixtures  of  Chromic  and  Osmic  Acids  for  His- 
tological Purposes. — Dr.  Max  Flesch  recommends  |  this  mixture  in 
the  following  proportions  : — 

Osmic  acid 0"10 

Chromic  acid       0  •  2.5 

Distilled  water 100-00 

It  answers  particularly  well  for  the  auditory  organs  of  smaller  animals, 
many  of  the  details  of  structure  of  the  cochlea  coming  out  with  quite 
diagrammatic  clearness.  The  hairs  of  the  hair-cells  are,  however, 
mostly  lost.  It  also  answers  well  for  examining  the  growth  of  bone 
in  the  epiphyses  of  small  animals,  and  for  general  views  of  retina,  con- 
junctiva, cornea,  and  the  eyelids  ;  in  these  latter  many  details  suffer, 
especially  the  bacillary  layer  of  the  retina. 

The  objects  for  examination  are  placed  fresh  in  the  fluid,  and  kept 
there  from  twenty-four  to  thirty-six  hours.     There  is  no  need  to  keep 

*  See  the  journal  'Apiculture,'  August,  1878. 

t  'Zool.  Anzeiger,'  vol.  i.  (1878). 

X  '  Archiv  f.  Mikr.  Auat.,'  vol.  xvi.  (1878). 


NOTES   AND    MEMORANDA.  145 

them  in  the  dark,  as  the  osmic  acid  in  conjunction  with  chi'omic  does 
not  undergo  such  rapid  changes  by  light  as  when  alone.  In  the  case  of 
cochlea,  young  bones,  &c.,  a  further  treatment  with  0  •  25  to  0  •  5  per 
cent,  solution  of  chromic  acid  may  be  necessary  for  complete  decalci- 
fication. The  object  is  then  washed  and  placed  in  spirit,  and  the 
sections  may  then  either  be  examined  in  glycerine,  or  treated  succes- 
sively with  absolute  alcohol  and  turpentine,  and  then  mounted  in 
Canada  balsam. 

The  great  advantages  of  this  fluid  are  its  rapid  hardening  pro- 
perties, and  the  fact  that  no  further  staining  is  necessary,  the  osmic 
acid  imparting  sufficient  colour  to  the  cells,  even  when  mounted  in 
balsam.* 

Microscopical  Research  under  Difficulties. — Professor  Eay  Lan- 
kester,  writing  to  '  Nature,'  f  says  that  the  following  short  preface 
to  a  very  valuable  account  of  the  stages  of  development  from  the 
egg  of  one  of  the  centipedes  (GeopJdlus),  no  member  of  which  group 
had  been  studied  previously  to  this  account,  gives  so  convincing  a 
picture  of  the  enthusiasm  for  investigation  which  may  animate  the 
modern  naturalist,  that  he  extracts  it  for  the  encouragement  of  the 
"  craft." 

Elias  Metschnikoff  has  during  the  past  fifteen  years  worked 
more  assiduously  with  the  Microscoj)e  at  the  observation  of  the 
minute  details  of  embryology  than  any  other  student.  To  him  we 
are  indebted  for  our  first  accurate  knowledge  of  this  subject  in  the 
case  of  many  important  animal  forms,  e.  g.  sponges,  various  jelly-fishes, 
marine  worms,  the  scorpion,  and  the  book-scorpions,  various  insects, 
crustaceans,  starfishes,  and  ascidians.  One  result  has  been  the  injury 
of  his  eye-sight.  In  his  memoir  on  Geopliilus,t  he  says : — "  After  having 
for  many  years  sought  in  vain  for  material  suited  for  the  investigation 
of  the  embryology  of  the  centipedes,  I  chanced  to  obtain  a  quantity 
of  the  eggs  of  Gcopliilm.  My  find,  however,  took  place  under  such  cir- 
cumstances, and  these  interfered  so  much  with  my  investigation,  that 
I  feel  justified  in  describing  them  more  minutely.  For  some  consi- 
derable time  I  had  been  affiicted  with  a  chronic  affection  of  the  eyes, 
and  consequently  commenced  in  the  spring  of  the  present  year  a 
journey  to  our  south-eastern  steppes  in  order  to  turn  my  attention  to 
anthropological  studies.  Instead  of  taking  with  me,  as  in  previoi;s 
years,  all  the  ajjparatus  necessary  for  microscopical  research,  I  took 
this  time  on  my  journey  only  anthropological  measuring  instruments. 
When,  then,  I  was  in  the  neighbourhood  of  Manytsch,  nearly  in  the 
heart  of  the  Kalmuk  steppes,  and  was  visiting  a  small  forest  planta- 
tion, I  discovered  quite  unexpectedly  a  number  of  eggs  of  Geo])kilus 
which  had  been  deposited  under  the  bark  of  a  rotten  tree-stem  where 
the  females  were  watching  over  them.  I  gathered  up  the  precious 
material,  and  having  packed  it  carefully  in  two  bottles,  set  off  with  all 

*  A  mixture  of  chromic  and  osmic  acids  for  embryological  purposes  was 
recommended  by  Dr.  A.  Milnes  Marshall  in  '  Quart.  Journ.  Micr.  Sci.,'  N.  S., 
vol.  xviii.  (1878). 

t  '  Nature,'  vol.  xix.  (1879)  p.  342. 

t  '  Zeitschrift  f.  wiss.  Zool.'  (1875). 
VOL.    II.  L 


146  NOTES  AND   MEMORANDA. 

speed  to  Astraclian,  in  order  there  to  set  about  the  roicroscopic  inves- 
tigation of  the  eggs.  But  when,  after  four  days'  travelling,  I  arrived 
in  a  Kussian  village,  Jandiki,  near  the  shore  of  the  Caspian  Sea,  and 
inspected  my  two  bottles,  I  found  in  them  only  a  couple  of  dead, 
opaque  eggs,  all  the  others  having  entirely  disappeared.  Fortunately 
I  succeeded  in  Jandiki,  where  there  is  also  a  small  plantation,  in 
obtaining  fresh  material  of  the  same  kind,  and  this  I  brought  in  good 
condition  to  Astrachan,  making  the  journey  by  steamboat.  In  the 
town  of  Astrachan  I  was  able  to  borrow  a  Hartnack's  Microscope  from 
a  medical  man  practising  there,  and  on  a  second  journey  took  it  with 
me  to  Jandiki.  In  this  way  I  was  enabled  to  make  out  the  chief 
features  of  the  developmental  history  of  Geophilus  by  the  use  of  my 
less  seriously  affected  left  eye.  At  the  same  time,  in  spite  of  the 
very  favourable  character  of  the  GeopMlus  eggs  for  microscopic  re- 
search, I  could  not  bring  my  work  to  the  desired  degree  of  complete- 
ness." 

Determination  and  pluck,  Professor  Lankester  adds,  have  their 
scope  in  embryology ! 

Degeneration  of  the  Visual  Organs  in  Arachnida. — Among 
the  group  of  pseudo-scorpions,  some,  such  as  CheUfer,  have  well- 
developed  eyes,  while  others,  such  as  Cliernes,  are  usually  said  to  be 
quite  devoid  of  visual  organs.  The  interesting  discovery  has,  however, 
been  made  by  Anton  Stecker,  of  Prague,*  that  certain  individuals  of 
the  latter  genus  possess  eyes,  although  in  a  rudimentary  condition.  In 
specimens  of  C.  cimicoides,  Stecker  observed  on  the  cephalo-thoracic 
shield,  in  the  position  of  the  eyes  of  CheUfer,  clear,  somewhat  trans- 
parent spots,  the  chitin  forming  them  being  devoid  of  the  granulations 
covering  the  rest  of  the  shield.  These  structures  have  quite  the 
appearance  of  corneas,  but  their  visual  nature  is  put  beyond  queslion 
by  the  remarkable  fact  that  each  is  supplied  by  a  large  and  well- 
developed  optic  nerve,  proceeding  from  an  optic  ganglion  in  connec- 
tion with  the  brain.  The  characteristic  anthropod  end-apparatus — 
the  layer  of  crystalline  rods — was,  however,  wholly  absent. 

About  30  to  35  per  cent,  of  the  specimens  of  Cherries  cimicoides 
examined  possessed  these  eye-spots  ;  in  the  remaining  65  to  70  per  cent, 
they  are  absent,  as  well  as  the  optic  nerves ;  while  there  was  only  one,  or 
even  no,  recognizable  rudiment  of  an  optic  ganglion.  It  was  also  made 
out  that  the  offspring  of  parents,  both  of  which  had  eyes,  were  them- 
selves provided  with  these  organs ;  but  that  if  either  the  father  or 
the  mother  were  blind,  the  young  were  blind  too,  having,  at  most,  a 
feeble  indication  of  optic  lobes. 

As  the  author  remarks,  we  have  here  a  most  instructive  case  of  the 
gradual  atrophy  of  an  organ  by  disease,  owing  to  the  influence  of  changed 
conditions.  There  can  be  little  doubt  that  the  ancestors  of  Chernes 
possessed  well-developed  eyes ;  the  disappearance  of  the  crystalline 
cones  and  of  the  characteristic  structure  of  the  cornea  seems  to  have 
been  the  first  step  in  the  retrogressive  process,  the  optic  nerve  and 
ganglion  remaining  in  a  fairly  well-developed  state  after  the  true  per- 

*  '  Morphologisches  Jahrbuch,'  vol.  iv.  (1878)  p.  279. 


NOTES   AND    MEMOBANDA.  147 

cipient  apparatus  had  gone.  It  is  an  interesting  circumstance  that  the 
optic  nerve  of  Cliernes  seems  to  have,  in  some  degree,  taken  on  the 
function  of  a  nerve  of  common  sensation,  since  many  of  its  fibres  are 
distributed  to  the  layer  of  connective  tissue  underlying  the  hypo- 
dermis. 

In  one  individual  of  the  same  species  a  curious  malformation 
occurred,  there  being  a  single  eye  m  the  middle  line  of  the  cephalo- 
thorax,  instead  of  the  usual  pair.  The  organ  in  question  had  a  slightly 
convex  cornea,  divided  into  hexagonal  areas  ;  beneath  this  was  a  layer 
of  crystalline  rods,  and  a  strongly  developed  layer  of  brown  pigment. 
This  thoroughly  well-formed  visual  organ  is  supplied  by  both  optic 
nerves,  which,  after  leaving  the  brain,  ran  forwards  parallel  with  one 
another,  to  the  layer  of  crystalline  rods. 

Two  cases  of  abnormal  organs  of  sight  were  also  met  with  in 
Chelifer  ixoides.  In  one  of  these  the  eye  on  one  side  was  perfectly 
normal,  but  on  the  other,  while  the  nerves  and  bacillary  layers  were 
well  developed,  the  cornea  formed  a  mere  speck,  like  the  eye-spots  of 
Chernes.  In  the  second  instance,  both  eyes  were  developed,  but  were 
so  small  as  to  be  hardly  visible ;  the  crystalline  rods  and  pigment,  at 
the  same  time,  were  much  reduced. 

Ascent  and  Circulation  of  the  Sap. — The  course  and  the  causes 
of  the  ascent  and  circulation  of  the  sap  in  plants  are  attracting  much 
attention  just  now  among  French  physiologists,  and  the  results  should 
be  carefully  studied  in  connection  with  the  recent  researches  of  M. 
Boussingault  and  the  Rev.  G.  Henslow  as  to  the  power  of  leaves  to 
absorb  water  in  the  fluid  or  gaseous  state.  A  recent  number  of  the 
botanical  series  of  the  '  Annales  des  Sciences  Naturelles '  *  contains 
three  articles  bearing  more  or  less  directly  on  this  subject.  In  the 
first  of  these,  "  On  the  Influence  of  the  Temperature  of  the  Soil  on 
the  Absorption  of  Water  by  the  Eoots,"  M.  J.  Vesque  arrives  at  the 
following  general  conclusions: — 

1st.  In  no  case  can  absorption  be  practically  separated  from  trans- 
piration, in  a  plant  imder  normal  conditions.  As  soon  as  the  absorp- 
tion exceeds  the  transpiration,  the  former  diminishes,  and  is  probably 
regulated  by  the  latter;  when  the  transpiration  is  suppressed,  the 
absorption  gradually  lessens,  and  finally  ceases.  The  reason  of  this 
phenomenon  doubtless  lies  in  the  manner  of  behaviour  of  the  air 
within  the  plant.  The  transpiration  ceasing  to  make  a  vacuum,  there 
comes  a  time  when  the  atmospheric  pressure,  plus  the  pressure  from 
the  roots,  is  incapable  of  overcoming  the  tension  of  the  internal  air 
and  the  resistance  of  filtration. 

2nd.  When  the  temperature  of  the  soil  is  rapidly  raised,  absorp- 
tion diminishes  in  consequence  of  the  increase  of  the  pressure  of  the 
air  contained  in  the  wood.  For  the  same  reason,  absorption  increases 
when  the  temperature  of  the  soil  is  rapidly  lowered. 

3rd.  Each  temperature  of  the  soil  being  considered  as  a  constant, 
the  absorption  increases  with  the  temperature  ;  except  perhaps  in  high 
temperatures,  where  the  question  has  not  yet  been  completely  worked 
out. 

*  'Ann.  cles  Sci.  Nat.'  (Bot.),  3rcl  ser.,  vol.  yI.  (1878)  p.  169. 

L    2 


148  NOTES   AND   MEMORANDA. 

4tli.  The  temperature  of  the  soil  has  much  less  influence  on 
absorption  than  that  of  the  air  (by  the  intermediation  of  transpiration) 
under  ordinary  conditions  of  moisture.  For  a  much  stronger  reason, 
it  is  of  but  little  consequence  for  a  plant  growing  in  the  open  air  to 
be  exposed  to  the  burning  rays  of  the  sun. 

The  same  author  follows  this  paper  by  one  "  On  the  direct  Com- 
jiarison  of  Absorption  with  Transpiration."  *  The  principal  conclu- 
sion to  which  a  long  and  careful  series  of  experiments  has  led  him,  is 
that  the  amount  of  absorption  does  not  bear  any  direct  proportion  to 
that  of  transpiration ;  and  his  general  results  are  summed  up  as 
follows : — 

1.  Of  all  the  theories  proposed  up  to  the  present  to  explain  the 
motion  of  the  water  in  the  plant,  that  of  Boehm  (referred  to  hereafter) 
is  most  in  harmony  with  observed  facts. 

2.  Although  transpiration  is  the  most  powerful  cause  of  absorp- 
tion, these  two  functions  are  not  necessarily  proportional. 

3.  Absorption  is  equal  (in  general  terms)  to  transj)iration  when 
the  i^lant  grows  in  average  and  very  slightly  varying  conditions ;  for 
example,  in  diffused  light  and  in  moderately  moist  air. 

4.  When  a  plant  removed  from  these  average  conditions  is  ex- 
posed to  dry  air,  transpiration  is  much  stronger  than  absorption.  It 
cannot  possibly  attain  so  high  a  figure  as  transpiration ;  the  plant 
withers,  and  it  is  exjjosed  to  an  irreparable  disturbance,  which  consists 
perhaps  in  the  abnormal  destruction  of  the  vacuum  existing  in  the 
plant. 

5.  When  a  plant  is  removed  from  these  average  conditions  of 
growth,  and  exposed  to  air  satiirated  with  moisture,  the  absorption, 
obeying  the  already  existing  vacuum,  is  stronger  than  the  transpira- 
tion ;  but  in  proportion  as  the  vacuum  fills  up,  the  absorption  decreases, 
and  finally  ceases  if  the  transpiration  has  also  ceased  (state  of  re- 
pletion). 

6.  When  a  plant  lacks  water,  the  suction  produced  by  transpi- 
ration is  not  lost ;  it  accumulates,  and  comes  into  operation  as  soon 
as  the  roots  come  in  contact  with  water.  An  absorption  much  more 
energetic  than  the  transpiration  is  then  observed ;  but  this  continues 
to  diminish  in  ]3roportion  as  the  existing  vacuum  fills,  to  be  finally 
regulated  by  the  intensity  of  transpiration. 

The  paper  by  M.  Boehm,  "  On  the  Causes  of  the  Ascent  of  Sap,"  f 
is  a  very  valuable  one  : — 

Even  now,  he  says,  the  majority  of  physiologists  consider  the 
movement  of  the  water  excited  by  transpiration  in  the  turgescent 
cells  of  the  leaves  to  be  a  purely  osmotic  phenomenon.  Owing  to  the 
continuous  production  of  organic  matter  in  the  assimilating  cells,  the 
osmotic  tension  would  always  have  such  an  intensity  that  the  water 
coming  from  the  neighbouring  cells  would  replace  the  loss  caused  by 
transpiration.  This  view  is,  however,  as  he  believes,  erroneous,  for 
the  following  reasons: — 

1st.  The  movement  of  water  produced  by  osmose  is  extremely  slow. 

*  '  Ann.  des  Sci.  Nat.'  (Bot.),  3rd  ser.,  vol.  vi.  (1S7S)  p.  201. 
t  Ibid.,  p.  223. 


NOTES   AND    MEMORANDA.  149 

2nd.  The  cells  whicli  directly  transpire — those  of  the  epidermis — 
are  generally  destitute  of  chlorophyll ;  they  do  not  assimilate,  and 
cannot  produce  matters  capable  of  causing  an  osmotic  diffusion.  It  is 
probable  that  they  contain  nothing  but  water,  which  cannot  be  con- 
centrated by  evaporation. 

3rd.  If  the  evaporated  water  is  replaced  by  the  action  of  osmose, 
the  leaves  of  the  plant  which  assimilate  in  moist  air  would  be  covered 
with  the  water  which  is  given  off,  and  the  intercellular  spaces  would 
also  become  filled  with  water.  This  has,  however,  never  been  ob- 
served. 

dth.  In  a  green  plant  exposed  in  a  damp  and  dark  place,  the  dif- 
ferences of  osmotic  tension  in  the  cells  of  the  leaves  would  gradually 
be  effaced  by  the  consumi)tion  of  the  osmotic  substances,  or  by  their 
departure  into  the  stem.  The  leaves  remain  fresh  when  the  plant 
is  transported  into  dry  air  without  permitting  access  of  light. 

5th.  If  the  movement  of  water  in  the  leaves  were  produced  by  the 
differences  in  density  of  the  contents  of  the  cells,  it  would  act  in  the 
same  manner  in  parenchymatous  wood,  a  supposition  which  will  not  be 
maintained. 

If  the  movement  of  water  in  the  leaves  is  not  due  to  osmose,  this 
is  still  more  the  case  with  wood,  the  cells  of  which  in  general  only 
contain  air  when  transpiration  is  very  active.  Some  authorities  be- 
lieved till  quite  recently  that  the  force  of  absorption  by  the  roots  may 
have  the  power  of  forcing  up  water  even  to  the  topmost  boughs  of 
trees.  But  a  considerable  number  of  facts  are  in  opposition  to  this 
theory.  In  a  great  number  of  cases  it  is  imj)ossible  to  prove  the 
existence  of  any  such  vis  a  tergo. 

M.  Boehm,  in  conclusion,  says  that,  in  the  parenchymatous  tissues 
filled  with  sap,  the  movement  of  water  excited  by  transpiration  is  a 
function  of  the  elasticity  of  the  cell-walls  and  of  the  atmospheric 
IH-essure,  and  in  cells  with  rigid  walls  the  elasticity  of  the  wall  is 
replaced  by  that  of  the  air  enclosed  in  the  cells.  The  presence  of  a 
certain  quantity  of  air  in  the  cells  of  the  wood  which  conduct  the  sap, 
far  from  being  a  hindi-ance  to  the  ascent  of  the  sap,  is  on  the  con- 
trary an  indispensable  agent  in  the  production  of  this  movement. 

Some  have  maintained  that  the  ligneous  cells  of  plants  in  full 
transpiration  contain  nothing  but  air,  and  that,  as  no  water  is  seen  in 
them,  therefore  there  is  none.  But  the  author  pointed  out,  as  much 
as  fifteen  years  ago,  when  all  micrograph  ers  believed  the  contrary, 
that  the  fibres  of  Coniferte  are  closed,  and  not  open.  The  position 
of  the  membrane  of  the  bordered  pits  eviJently  depends  on  the 
differences  of  tension  in  the  two  adjoining  cells,  and  corresponds  to 
the  direction  of  the  current  of  the  sap.  The  constant  presence  of  a 
certain  quantity  of  water  in  the  ligneous  conducting  cells  is  an  un- 
doubted fact. 

The  movement  of  the  tvater  excited  in  plants  hy  transpiration  is  a 
phenomenon  of  filtration  dependent  on  the  differences  of  pressure  in 
adjoining  cells. 

Growth  of  the  Root  of  Phanerogams. — M.  Ch.  Flahault  has 
made  an  elaborate  anatomical  study  of  the  structure  of  the  apex  of 


150  NOTES   AND   MEMORANDA. 

the  root  in  all  the  important  groups  of  Phanerogams.*  The  results  of 
his  investigations  show  that  the  characters  of  the  apex  of  the  root  cannot 
serve  for  the  appreciation  of  the  reciprocal  relations  of  the  families, 
and  that  the  views  of  M.  Treub  on  the  taxinomic  importance  of  these 
characters  are  not  well  founded.  Plants  most  closely  allied  often 
differ  very  much  in  the  structure  of  the  apex  of  their  roots,  and  on 
the  other  hand,  plants  belonging  to  widely  separated  families  have 
common  radicular  characters. 

The  structure  of  the  vegetative  summit  can  in  fact  only  serve  as 
regards  classification  to  establish  positively  whether  a  plant  is  a 
monocotyledon  or  a  dicotyledon. 

Removal  of  Air  from  Microscopic  Specimens.— Much  difficulty 
has  been  experienced  by  the  working  microscopist  in  removing  air 
from  his  specimens,  especially  with  wood  sections,  and  various 
methods  have  been  adopted  with  greater  or  less  success.  One  method 
has  been  to  soak  the  specimens,  after  they  have  been  cut,  in  different 
fluids  for  some  length  of  time,  such  as  turpentine,  oil  of  cloves,  and 
the  like ;  these,  however,  give  very  unsatisfactory  results,  sections  of 
wood  having  lain  in  oil  of  cloves  for  over  three  years  without  the  air- 
bubbles  having  been  all  removed.  Eecourse  has  also  been  had 
ineffectually  to  the  air-pump,  and  microscopists  have  been  at  their 
wits'  end  to  discover  some  process  by  which  their  object  can  be 
perfectly  and  satisfactorily  accomplished. 

It  is  claimed  t  for  Dr.  Johnson,  of  Providence,  E.I.  (U.S.),  that  he 
has  discovered  an  effective  method.  The  apparatus  he  employs  is  of 
very  simple  construction,  being  a  digester,  or  a  common  dentist's 
vulcanizer,  the  means — steam.  The  specimens  to  be  thus  treated, 
especially  those  of  wood,  are  prepared  in  the  usual  way,  and  made 
ready  for  mounting.  They  are  nest  placed  in  a  small  vessel  of  any 
material  which  will  resist  a  certain  amount  of  heat.  Dr.  Johnson  uses 
a  small  glass  phial  in  his  experiments ;  this  is  filled  up  with  water 
after  all  the  specimens,  as  many  as  it  can  conveniently  hold,  are 
placed  within.  A  cork  can  be  used,  but  a  slit  must  be  cut  in  it  to 
allow  the  escape  of  air  and  the  admission  of  steam  and  hot  water. 
A  little  water  is  now  poured  into  the  vulcanizer,  the  bottle  of  objects 
placed  within,  and  the  lid  of  the  machine  screwed  air-tight.  The 
whole  is  then  heated  to  a  temperature  of  about  300°  Fahr.  for  a  few 
minutes.  This  temperature  is  sufficient  for  all  practical  purposes ;  a 
higher  degree  of  heat  is  unnecessary,  or  a  longer  time  to  remain  at  the 
given  temperature  needless. 

When  sufficiently  cooled  the  phial  is  removed,  the  water  drained 
from  the  bottle,  and  alcohol  substituted.  The  specimens  are  now 
ready  for  mounting,  or  can  be  bottled  and  set  away  indefinitely  for 
use. 

This  constitutes  the  whole  process;  by  it  the  specimens  are 
absolutely  free  from  air.  Perfect  satisfaction  is  guaranteed  ;  and  in 
every  case  we  are  absolutely  sure  of  the  results,  provided,  of  course, 
that  the  proper  care  has  been  taken. 

*  'Ann.  Sci.  Nat.'  (Bot.),  Gth  ser.,  vol.  vi.  (1878). 
t  'American  Naturaliat,'  vol.  xiii.  (1879)  p.  57. 


NOTES   AND    MEMOEANDA.  151 

The  modus  operandi  seems  to  be  that  the  steam  penetrates  the 
pores  of  the  wood  or  other  substances,  and  forces  out  the  air,  whose 
place  it  takes.  The  air  is  then  absorbed  by  or  dissolved  in  the  sur- 
rounding medium.  The  woody  fibres  are  not  destroyed  by  the  hot 
and  compressed  steam,  except  the  soft  tissues,  as  one  would  at  first 
sight  suppose.  They  are  entirely  uninjured,  and  their  purposes  for 
microscopic  study  remain  as  good  as  by  any  other  process.  Tender 
specimens  in  every  case  must  be  tenderly  treated.  This  mode  of 
procedure  has  been  followed  by  several  microscopists  in  America  for 
two  or  three  years,  and  all  the  specimens  so  treated  have  been  remarked 
for  their  beauty  and  excellence. 

Immersion  Illuminators. — Mr.  Wenham  thinks  that  too  much  is 
said  in  favour  of  the  prism  which  he  described  in  1856  *  (intended  to 
be  attached  to  the  under  surface  of  the  slide  by  oil  of  cloves),  by  some 
who  take  it  up  as  a  recent  discovery.  He  at  once  abandoned  it  in 
favour  of  a  lens  nearly  hemispherical,  of  about  ^^  radius,  which  is 
much  more  convenient  and  effective  for  all  purposes,  and  less  costly. 
This  lens  is  then  attached  to  the  under  side  of  the  slide  by  the  oil,  in 
the  same  way  as  the  prism,  or  it  may  be  set  in  a  thin  plate  of  brass  to 
be  slid  under  the  slide  and  centred  under  a  low  power  if  necessary ; 
or  otherwise  mounted  in  a  sub-stage  fitting  of  such  a  form  as  not  to 
interfere  with  the  passage  of  the  most  oblique  rays  that  can  be  sent 
into  it  sideways,  which  are  by  this  appliance  transmitted  straight  to 
the  object.  When  used  with  a  dry  objective,  the  object  is  seen  on  a 
dark  field,  the  rays  being  reflected  from  the  top  of  the  cover,  which 
acts  as  a  Lieberkuhn.| 

In  a  letter  to  ourselves  Mr.  Wenham  says  that  he  finds  no  illu- 
minator equals  it,  for  he  can  immediately  bring  out  Ampliipleura 
without  the  least  trouble,  even  when  mounted  in  balsam  ;  a  feat  that 
has  sometimes  before  cost  him  half  an  hour's  work. 

Phosphorescence  of  the  Flesh  of  Lobsters. — The  following  view 
of  the  cause  of  this  phosphorescence  is  put  forward  by  Messrs.  Bancel 
and  Husson.J  The  first  alteration  observed  in  the  flesh  of  marine 
animals  is  the  formation  of  a  gelatinous  substance,  and  it  is  then 
that  phosphorescence  appears. 

Examined  under  the  Microscope,  two  kinds  of  germs  are  seen ;  on 
the  surface,  cells  which  without  doubt  produce  this  kind  of  mucous 
fermentation ;  in  the  mucus,  infinitely  small  bacteria. 

The  former,  which  are  of  a  reddish  yellow,  are  aerobic,  and 
appear  to  act  as  plants,  that  is,  that  during  the  day  they  decompose 
the  carbonic  acid  of  the  air,  fixing  the  carbon  and  setting  the  oxygen 
free,  which  remains  in  solution  in  the  liquid. 

If  this  liquid  contains  an  anaerobic  germ,  its  development  is  arrested 
— it  is  anaesthetized.  But  in  the  night  the  cell  disengages  carbonic 
acid,  the  germ  lives,  and  the  consequences  are  the  destruction  of  the 

*  '  Quart.  Joum.  Mic.  Sci.,'  vol.  ii.  (1856)  p.  2;  and  see  this  Journal,  vol.  i. 
(1878)  p.  309. 

t  'English  Mechanic,'  vol.  xxviii.  (1879)  p.  501. 
X  '  Comptes  Kendus,'  vol.  Ixxxviii.  (1879)  p.  191. 


152  NOTES    AND    MEMORANDA. 

surrounding  matters,  with  condensation  of  oxygen  on  one  hand,  and  on 
the  other  the  production  of  carburetted  and  phosphuretted  hydrogen 
when  the  medium  contains  phosphates. 

When  the  oxidizing  power  of  the  ferments  is  considered,  it  is  seen 
tbat  these  hydrogenous  products  are  burnt  in  proportion  as  they  are 
formed,  and  thus  the  phosphorescence  is  explained. 

All  the  facts  observed  prove  that  the  phosphorescence  of  the 
lobster  is  due  to  an  analogous  fermentation.  This  is  confirmed  by 
the  fact  that  the  ferment  of  the  phosphorescence  is  destroyed  by  the 
putrid  ferment  in  the  same  way  as  the  vibrions  of  putrefaction  stifle 
the  bacteria  of  anthrax. 

Species  of  Marine  Crustacea  in  Lake  Erie. — At  the  meeting  of 
the  Buffalo  Microscopical  Club,  of  the  10th  November  last.  Professor 
D.  S.  Kellicott  communicated  a  note  on  the  discovery  of  a  species  of 
marine  Crustacea  in  the  waters  of  Lake  Erie.  He  had  captured  a 
species  of  Mysis  in  the  hydrant  water,  thus  confirming  the  previous 
detection  of  these  creatures  in  the  waters  of  the  great  lakes  by 
Stimpson  and  Hoy.* 

It  is  not  stated  whether  the  species  is  3Iysis  relicta,  which  is  well 
known  to  inhabit  the  fresh-water  lakes  of  Norway  and  Sweden  as 
well  as  America. 

Professor  Kellicott  also  stated  that  the  body  of  the  Mysis  was 
covered  with  a  marine  Protozoa,  Acineta  tuherosa,  a  matter  interesting 
in  connection  with  the  fact  recently  mentioned  by  Professor  H.  L. 
Smith,!  of  the  occurrence  of  marine  forms  of  diatoms  in  the  waters 
of  the  lakes. 

Gigantic  Isopod  of  the  Deep  Sea. — Professor  Alexander  Agassiz 
has  sent  to  M.  A.  Milne-Edwards  the  Crustacea  collected  by  him  in 
December,  1877,  from  dredgings  in  the  Gulf  Stream  between  Florida 
and  Cuba.  Amongst  them  was  an  Isopod  obtained  at  955  fathoms, 
which  was  remarkable  not  only  by  its  relatively  enormous  dimensions, 
9  inches  X  4  inches,  but  by  the  sj)ecial  arrangement  of  its  resj)iratory 
apparatus,  which  is  very  different  from  that  of  all  other  known 
Crustacea.  M.  Milne  -  Edwards  proposes  to  call  it  Baihynomus 
giganteus.'l 

It  would  seem  that  the  respiratory  apparatus  of  an  ordinary 
Isopod  is  insufficient  for  the  physiological  wants  of  Batliynomus,  and 
that  it  requires  special  apparatus  of  much  greater  functional  power. 
The  false  abdominal  feet  which  ordinarily  constitute  the  branchial 
apparatus,  only  form  in  Batliynomus  a  kind  of  opercular  system 
under  which  are  found  the  true  branchiae.  These  taken  separately 
resemble  small  branching  tufts  or  plumes  growing  out  of  stems 
which  divide  more  and  more  and  form  long  hair-like  filaments. 
When  examined  with  a  magnifying  glass  it  is  seen  that  they  form  a 
certain  number  of  distinct  branches  more  or  less  developed,  and 
that  each  of  these  branches  arises  from  or  grows  out  of  a  tubular 

*  '  Amer.  Jour,  of  Microscopy,'  vol.  iii.  (1878)  p.  284. 

t  See  this  Journal,  vol.  i.  p.  368. 

X  'Comptes  Reudus,'  vol.  Ixxxviii.  (1879)  p.  21. 


NOTES    AND    MEMORANDA.  153 

peduncle  with  membranous  and  flexible  walls  which  soon  bifurcate  to 
form  other  branches ;  these  are  resolved  into  a  number  of  elongated 
filaments  nearly  alike,  but  without  regularity,  and  having  the  appear- 
ance of  a  spindle  with  delicate  walls. 

If  some  coloured  liquid  is  injected  into  the  sinus  at  the  base  of 
the  branchial  feet,  the  whole  of  this  system  may  be  easily  filled  and 
the  liquid  followed  not  only  in  the  branchial  tuft,  but  also  in  an 
irregular  network  sunk  in  the  thick  part  of  one  of  the  leaflets  of  the 
false  abdominal  feet  and  comparable  to  the  entire  branchial  apparatus 
of  the  ordinary  Isopods.  A  marginal  vessel  serves  to  collect  the  blood 
and  to  send  it  into  the  branchio-cardiac  trunk. 

In  all  the  other  Isopods  the  false  abdominal  feet  are  very  simple, 
and  wherever  they  are  complex  to  meet  the  requirements  of  a  more 
active  circulation,  it  is  by  the  rudimentary  foldings  of  the  posterior 
plate  of  these  members. 

In  lone  and  Kepon  *  branched  appendages  are  found  on  the  sides 
of  the  body,  but  there  are  fundamental  differences  between  these  and 
Bathynomus,  not  only  in  the  position  of  the  plumes,  but  in  their 
structure  also. 

Though  inhabiting  great  depths,  the  eyes  are  well  developed,  each 
having  about  4000  facets,  and  in  place  of  being  at  the  toj)  of  the  head 
they  occupy  its  inferior  face,  and  are  placed  beneath  the  frontal 
margin  on  each  side  of  the  base  of  the  antennae. 

Bathynomus  is  separated  by  important  characters  from  all  other 
Isopods,  and  justifies  its  being  placed  in  a  new  family  of  "  brauch- 
iferous  Cymothoadians." 

Limicolous  Cladocera. — In  the  introductory  part  of  a  paper  on 
these  Entomostraca,!  Dr.  W.  Kurz  gives  an  account  of  the  main 
difference  between  these  mud-dwellers  and  their  free-swimming 
congeners.  The  distinctive  characters  of  the  former  are  due,  firstly, 
to  the  increased  pressure  of  water  to  which  they  are  subjected ; 
secondly,  to  the  thickness  of  the  mud  in  which  they  live ;  and  thirdly, 
to  the  altered  relation  of  the  gases  absorbed  in  the  water  at  a 
considerable  depth  below  the  surface.  The  first  two  of  these  con- 
ditions give  rise  to  the  thick  integument  and  clumsy  form  which 
characterize  the  limicolous  species.  The  carapace  is  strengthened 
either  by  the  thickening  of  its  cuticle  or  by  the  remarkable  circum- 
stance that,  at  the  moult,  the  old  armour  is  not  cast  ofP,  but  remains 
superposed  on  the  newer  and  larger  parts  beneath,  like  an  old-fashioned 
"  spencer "  over  a  coat ;  three  or  four  carapaces  of  progressively 
increasing  size  may  thus  be  seen  in  a  single  individual.  The 
antennae  of  the  limicolous  forms  are  comparatively  very  short  and 
stout,  and  the  setae  on  them  are  not  feathered.  The  whole  body  has 
a  rounded  form,  and  the  brood-pouch  is  extended  laterally,  not 
vertically  as  in  the  free  forms.  As  a  rule  they  swim  with  the 
dorsal  surface  downwards.  The  power  of  swimming  seems  to  be  in 
inverse  ratio  to  the  size  of  the  post-abdomen  and  the  complexity  of 

*  Spelt  Kepon  by  A.  Milne-Edwurds ;  Kcponc  by  Adam  White ;  and  Cepon  by 
Duvcrnoy. 

t  'Zeitsch.  f.  wibs.  Zoologie,'  vol.  xxx.  Suppl.  (1878)  p.  3[)2. 


164  NOTES    AND    MEMORANDA. 

its  armature  of  spines  and  setaa.  The  chitin  of  the  limbs  and  other 
parts  covered  by  the  carapace  is  very  thin,  so  that  the  respiratory 
surface  is  much  increased.  It  is  doubtful  whether  this  is  due  to  the 
paucity  of  oxygen  in  the  medium  inhabited,  or  the  thickness  of  the 
carapace  and  its  consequent  unfitness  for  respiratory  purposes,  or 
because  of  the  exertion  of  burrowing  through  the  mud  which  these 
animals  have  to  undergo.  The  compound  eyes  are  always  much 
reduced,  or  may  even  be  entirely  absent.  At  the  same  time  the 
simple  eyes  are  increased  in  size  and  importance,  being  sometimes 
larger  than  the  compound  eyes,  and  sometimes  having  the  whole 
visual  function  assigned  to  them. 

The  remainder  of  the  paper  is  taken  up  with  a  description  of  the 
typical  genus  Uyocryptus,  and  of  its  various  species,  the  chief  points 
in  the  anatomy  of  which  are  illustrated  in  the  plate  which  accom- 
panies the  paper. 

New  Cryptogamic  Journals.  —  In  addition  to  '  Brebissonia,'  a 
monthly  journal  devoted  to  Algology,*  which  first  appeared  in  July 
last  year,  and  the  bi-monthly  '  Kevue  Bryologique,'  which  has  existed 
for  five  years,  we  now  have  a  new  journal,  published  every  three  weeks, 
for  Fungi — the  '  Eevue  Mycologique,'  edited  by  M.  C.  Roumeguere, 
the  first  number  of  which  appeared  in  January  last.  The  contents  of 
this  nimiber  will  be  foimd  noted  in  "  Bibliography." 

Unit  of  Micrometry. — We  stated  at  p.  353  of  vol.  i.  that  the  reso- 
lution of  the  Indianapolis  Congress,  which  recommended  the  y^  of  a 
millimetre  as  the  unit  of  micrometry,  was  approved  by  the  New  York 
Microscopical  Society.  At  a  subsequent  meeting,  however,  some  of 
the  members  had  the  subject  reconsidered,  and  the  former  approval 
was  unanimously  rescinded.  The  editor  of  the  '  American  Journal  of 
Microscopy,'  to  whose  views  reference  was  also  made  at  p.  353,  says 
the  action  of  the  Congress  "  is  now  generally  considered  to  have 
been  too  positive  and  definite,  for  the  simple  reason  that  the  subject 
had  not  been  sufficiently  discussed  or  considered  by  the  members 
present." 

The  Microscopical  Section  of  the  Troy  Scientific  Association  have 
appointed  a  committee  to  confer  with  other  microscopical  Societies  on 
the  subject  of  micrometry,  and  that  committee,  by  a  circular  issued  in 
December  last,  suggest  the  appointment  of  a  larger  committee  (on 
which  each  Society  should  be  represented  by  a  member),  whose  duty  it 
shall  be  to  investigate  the  questions  mentioned  below,  confer  with 
the  Societies  and  with  persons  known  to  be  experts  in  this  depart- 
ment, and  report  to  the  American  Society  of  Microscopists,  at  their 
next  meeting  at  Buffalo  in  August.  They  state  that  their  Society, 
whilst  earnestly  desiring  the  success  in  some  practicable  form  of  the 
movement  suggested  by  the  Congress,  believe  that  much  further  pre- 
paration will  be  required  to  enable  the  American  Society  to  take 
definite  action,  and  that,  to  prevent  the  movement  being  a  failure,  it 
must  be  entered  upon  after  mature  deliberation  and  full  consultation, 
and  in  such  manner  as  to  secure  the  general  and  cordial  assent  of 
*  Sec  thia  Journal,  vol.  i.  (1878)  p.  368. 


NOTES  AND  MEMORANDA.  155 

those  who  are  prominently  interested  in  and  qualified  to  judge  of  the 
subject.  To  secure  the  preliminary  investigation  and  the  moral  power 
necessary  to  this  end,  if  the  end  is  now  attainable  at  all,  they  invite  the 
co-operation  of  the  Societies  as  above  mentioned,  as  well  as  of  micro- 
scopists  generally. 

The  questions  are  as  follows  : — 

(1)  Is  it  expedient  at  present  to  adopt  a  standard  for  micro- 
metry ? 

(2)  If  so,  should  the  English  or  the  metric  system  be  employed  ? 

(3)  "What  unit  within  the  system  selected  is  most  eligible  ? 

(4)  What  steps  should  be  taken  to  obtain  a  suitable  standard 
measure  of  this  unit  ? 

(5)  How  can  this  standard  micrometer  be  best  preserved,  and  made 
useful  to  all  parties  concerned  ?  * 

M.  G.  Huberson,  the  editor  of  '  Brebissonia,'  thinks  f  it  "  is  sad 
that  a  second  micrometric  unit  should  be  established  in  the  New 
World,  when  the  Old  World  has  already  for  a  number  of  years  adopted 
the  y^Vo  o^  ^  millimetre  as  the  unit  of  micrometric  measurements,  on 
the  proposition  of  Professor  Suringar,  of  Leyden  (Holland)." 

The  Tomopteridae. — The  interesting  pelagic  Chaetopods  ("  errant " 
Annelides)  which  constitute  the  two  genera  of  this  family,  have  been 
investigated  by  Gruber,  Leukart,  Carpenter,  Claparede,  and  others. 
Eecently,  Dr.  Franz  Vejdovsky,  of  Prague,  has  taken  up  the  subject, 
and  contributes  a  paper  to  Siebold  and  Kolliker's  '  Zeitschrift,'  |  illus- 
trated by  two  excellent  plates,  and  dealing  chiefly  with  certain  points 
in  the  anatomy  of  T,  vitrina. 

1.  Nervous  System  and  Sense  Organs. — There  is  a  great  amount  of 
discrepancy  between  the  accounts  of  the  central  nervous  system  given 
by  different  authors.  Busch  described  a  brain  consisting  of  two  united 
ganglia,  but  saw  no  ventral  nerve-cord ;  the  latter  was  described  by 
Gruber  and  by  Kefertein,  but  Leukart  and  Pagenstecher  saw  only 
the  brain,  and  Carpenter  and  Claparede  described  in  T.  onisciformis  a 
single  fibre  passing  from  the  latter  along  the  dorsal  side  of  the  animal, 
but  denied  the  existence  of  the  ventral  cord  and  circumoesophageal 
commissures. 

The  nervous  system  of  T.  vitrina  was  investigated  by  Vejdovsky, 
both  in  the  fresh  condition  and  after  treatment  with  osmic  acid, 
alcohol,  and  picro-carmine.  The  brain  is  of  a  somewhat  triangular 
shape,  the  base  being  in  front ;  from  its  anterior  angles  the  tentacular 
nerves  are  given  off,  while  from  its  ventral  surface  proceed  the  circum- 
cesophageal  commissures,  which  curve  round  the  gullet,  some  of  their 
fibres  uniting  with  one  another  in  the  middle  ventral  line,  while  others 
are  continued  backwards  into  the  ventral  nerve-cords,  a  small  interval 
being  left  between  the  latter.  In  this  interval  lies  a  longitudinal  row  of 
nerve-cells,  while  another  row  is  situated  immediately  external  to  each 
of  the  ventral  cords,  so  that  there  are  three  distinct  rows  of  nerve- 

*  '  Amer.  Jour,  of  Microscopy,'  vol.  iii.  (1878)  p.  279. 

t  '  Brebissonia,'  vol.  i.  (1878)  p.  80. 

X  'Zeitsch.  f.  wiss.  Zoologie,'  vol.  xsxi.  (1878). 


156 


NOTES    AND    MEMOKANDA. 


cells — one  median  and  two  lateral — separated  from  one  another  by  the 
fibrous  cords.  The  space  between  the  two  latter,  which  is  wider  above 
than  below,  is  probably  the  remains  of  the  primitive  medullary  groove. 
The  lateral  rows  of  nerve-cells,  although  continuous,  present  accumu- 
lations at  intervals,  corresponding  to  ganglia.  These  spots  are  marked 
in  the  recent  state  by  patches  of  violet  pigment,  from  which  pro- 
longations are  continued  along  the  nerves. 

The  eyes  are  seated  directly  upon  the  brain  ;  the  lens  is  single,  not 
double  as  in  other  species ;  the  pigment  is  black.  The  structures 
situated  just  in  front  of  the  brain,  and  described  as  vesicles  by  Car- 
penter and  Claparede,  were  only  seen  in  one  specimen,  and  are  in 
reality  pits,  possibly  of  a  sensory  nature,  although  no  nerve-supply 
was  made  out  to  them. 

One  of  the  most  important  points  in  the  paper  is  the  interpretation 
given  by  Vejdovsky  to  the  anomalous  "  rosette-like  organs "  of  the 
parapodia.  One  of  these  is  situated  near  the  edge  of  the  fin-like 
expansion  of  both  notopodium  and  neuropodium ;  it  is  of  a  bright 
yellow  colour,  and  consists  of  five  to  seven  prismatic  bodies  arranged 
in  a  circle.  This  is  all  that  can  be  seen  in  the  fresh  state ;  but  after 
treatment  with  osmic  acid,  alcohol,  and  picro-carmine,  the  yellow 
rosette  is  stained  black,  and  the  prisms  of  which  it  is  composed 
become  very  distinct,  and  are  seen  to  be  surrounded  by  a  fine  homo- 
geneous investing  membrane ;  abutting  against  their  upper  ends  is 
seen  a  convex,  highly  refracting  lens,  while  at  the  base  of  ^he  rosette 
is  a  clear  roundish  area,  surrounded  by  a  zone  of  nerve-cells,  from 
which  fibres  are  given  ofi"  to  the  pigment  of  the  prisms.  The 
"  rosette-like  organ "  is  thus  proved  to  be  a  parapodial  eye :  the 
animal  possesses  two  of  these  visual  organs  to  each  parapodium,  over 
and  above  the  already  known  cephalic  eyes. 

2.  Sexual  Products  and  Seminal  Ducts. — The  ova  begin  as  groups 
of  cells  formed  on  the  living  membrane  of  the  prolongations  of  the 
body-cavity  into  the  parapodia.  These  groups  become  detached,  and 
float  freely  in  the  perivisceral  fluid ;  of  the  cells  of  which  they  are 
composed,  one  develops  at  the  expense  of  its  sister-cells,  and  becomes 
an  ovum.  No  external  aperture  for  the  escape  of  the  eggs  was  ob- 
served. 

The  seminal  cells  have  a  similar  origin :  the  ripe  spermatozoa 
escape  from  the  body  by  the  segmental  tubes.  These  organs  consist 
of  a  tubular  ciliated  internal  portion,  opening  into  the  perivisceral 
cavity  by  a  funnel-shaped  aperture  with  a  rosette-like  ciliated  border, 
and  of  a  dilated  external  portion  opening  on  the  surface  of  the  body 
by  a  rounded  aperture.  The  dilated  half  of  the  tube  acts  as  a  vesi- 
cula  seminalis.  In  the  posterior  part  of  the  body  the  spermatozoa 
become  aggregated  into  rounded  masses  (Samenklurapen),  devoid  of 
an  investing  membrane,  but  mistaken  for  testes  by  Carpenter  and 
Claparede. 

The  paper  concludes  with  a  discussion  of  the  various  species  of 
Tomojpteris  and  EschscJioltzia,  the  two  genera  of  Tomopteridfe. 

Abnormal  Sexual  Organs  in  the  Horse-Leech. — A  very  curious 
variation  from  the  ordinary  type  of  generative  organs  is  described  by 


NOTES   AND    MEMORANDA.  157 

Dr,  G.  Asper,  of  Zurich.*  In  the  horse-leech  (Aulastovia  gulo),  as  in 
other  Gnatliohdellidce,  the  male  organs  usually  consist  of  nine  to  twelve 
testes  on  each  side  of  the  body,  opening  into  a  common  vas  deferens, 
which  is  convoluted  anteriorly,  forming  the  vesicula  seminalis.  From 
each  vesicula  seminalis  the  seminal  duct  is  continued  into  the  base  of 
the  single,  median  penis.  The  ovaries  are  two  in  number,  one  on  each 
side ;  each  is  connected  with  a  short  oviduct,  which  joins  with  its 
fellow  to  form  a  common  canal  continuous  with  the  muscular  vagina. 

The  peculiarity  of  the  abnormal  form  consisted  in  the  fact  that 
the  duct  from  each  vesicula  seminalis  led  to  a  separate  penis,  so  that 
there  were  two  perfectly  distinct  intromittent  organs,  one  opening 
on  the  twentieth,  the  other  on  the  twenty-fifth  segment.  A  similar 
bilateral  arrangement  existed  in  the  female  organs.  An  ovary  was 
found  in  the  twenty-fifth  segment,  near  the  corresponding  penis,  its 
duct  having  a  common  opening  with  the  latter.  A  similar  female 
apparatus,  consisting  of  ovary  and  oviduct,  occurred  in  the  thii'tieth 
segment  of  the  opposite  side. 

The  Early  Development  of  Equisetaceae. — Taking  Hofmeister's 
account  of  the  development  of  the  JEquisetacece,  it  was  very  difficult  to 
make  out  the  exact  relation  between  the  first  stages  of  the  embryo  in 
this  group,  and  the  corresponding  stages  in  the  other  vascular  Crj-pto- 
gams.  In  Mr.  Vines's  paper  "  On  the  Homologies  of  the  Suspensor,"  t 
the  horse-tails  are  purposely  left  out  of  consideration  in  the  com- 
parison drawn  between  the  embryos  of  Phanerogams  and  of  the  hif^her 
Cryptogams.  But  the  difficulty  seems  to  be  quite  cleared  up  by 
Sadebeck's  recent  paper,|  in  which  the  early  stages  in  an  Equisetum 
arvense  and  E.  palustre  are  carefully  described,  and  are  seen  to  corre- 
spond very  exactly  with  those  of,  for  instance,  the  fern  Ceratopteris. 

The  first  septum  makes  an  angle  of  about  70°  with  the  axis  of  the 
archegonium,  and  divides  the  oosphore  into  two  cells,  an  upper,  the 
embryo  proper,  turned  towards  the  neck  of  the  archegonium,  and  a 
lower,  the  embryophore,  the  homologue  of  the  suspensor  of  Phanero- 
gams and  of  Selaginella.  Each  of  these  cells  is  then  divided  by  a 
septum  at  right  angles  to  the  first,  so  that  four  quadrants  are  produced 
the  two  upper  belonging  to  the  embryo,  the  two  lower  to  the  embrj^o- 
phore.  Of  the  former,  one  becomes  the  apical  cell  of  the  plant,  soon 
assuming  the  characteristic  form  of  a  short  three-sided  pyramid  with 
convex  base ;  the  other  becomes  the  first  leaf.  The  latter,  alon^  with 
the  two  first  segments  cut  oft'  from  the  apical  cell,  forms  the  first  leaf- 
sheath  of  the  young  plant.  Of  the  two  lower  quadrants,  one  becomes 
the  "  foot,"  a  temporary  organ  for  the  absorption  of  nutriment  from 
the  prothallus,  the  other  becomes  the  first  root,  an  apical  cell  being 
formed,  from  which  the  base  is  soon  cut  oft'  by  a  tangential  septum 
producing  the  root-cap. 

Anew  Rotifer— Anuraea  Ion gispina.— Professor  D.  S.  Kellicott,  of 
Bufialo,  U.S.,  has  found  §  a  rotifer  in  Niagara  water  at  that  place 
*  '  Zool.  Anzeiger,'  vol.  i.  (1878)  p.  297. 
t  '  Quart.  Jouru.  of  Micr.  Sci.,'  N.  S.,  vol.  xviii.  (1878). 
X  '  Jahrbliclier  f.  wiss.  Botauik,'  vol.  xi.  (1878). 
§  '  American  Journal  of  Microscopy,'  vol.  iv.  (1879)  p.  20. 


158 


NOTES   AND    MEMORANDA. 


having  very  .long  formidable-looking  setae,  to  which  he  proposes  to 
give  the  name  of  Anurcea  longispina,  the  long-spined  Anuria. 

We  have  shown  the  description  and  drawing  to  Dr.  Hudson,  who 
considers  the  claim  of  "  new  "  to  be  properly  made,  though  the  draw- 
ing is  probably  a  little  "  free  "  as  regards  the  internal  organs.  Not 
having  seen  the  animal  ourselves,  we  are,  of  course,  unable  to  do  more 
than  reproduce  the  woodcut  in  facsimile. 


The  description  of  the  rotifer  is  as  follows : — Lorica  ovate- 
cuneate,  smooth  on  both  the  dorsal  and  ventral  surfaces ;  it  has  seven 
frontal  and  one  terminal  spine ;  the  frontal  spine  situate  on  the 
middle  of  the  upper  margin  is  about  twice  as  long  as  the  carapace ; 
seen  from  above  it  is  straight,  from  side  arched ;  those  at  the  angles 
are  equal  in  length  to  the  carapace,  curved  outwards  and  downwards ; 
there  is  a  short  one  on  either  side  of  the  long  central  one,  also  two 
short  ones  on  the  margin  of  the  ventral  surface ;  they  seem  to  form 
ribs,  nearly  to  the  middle,  designed  to  strengthen  the  ventral  plate  of 
the  lorica,  so  that  it  opens  and  shuts  the  front  by  a  hinge-like  motion 
at  the  middle,  similar  to  the  lower  shell  of  a  Box  turtle  ;  the  terminal 
spine  is  somewhat  longer  than  the  lorica,  straight  seen  from  above, 
cynosuric  in  side  view.  The  three  long  frontal  spines  when  highly 
magnified,  always  appear  rough,  like  the  surface  of  the  carapace  of 
Ceratium  longicorne  ;  the  terminal  one  is  always  smooth. 

The  buccal  funnel  situated  in  the  lower  middle  part  of  the  face 
between  the  trochal  lobes  is  deep  and  ciliated ;  on  its  upper  border  is 
a  projecting  conical  lip  well  ciliated  ;  these  cilia  seem  to  be  able  to 
close  over  the  mouth  to  aid  in  the  retention  of  the  prey.  The  mallei 
and  incus  of  the  mastax  are  easily  made  out,  and  are  of  the  typical 
form.  (Esophagus  short,  digestive  cavity  clearly  divided  into  a 
capacious  gastric  expansion,  and  an  intestine,  or  cloaca.  The  two 
glands,  one  on  either  side  of  the  oesophagus,  are  distinct,  round  in 
one  aspect,  oblong  in  another.  Eye  large,  round,  red.  Egg  attached. 
Length,  including  the  spines,  ^^  of  an  inch  ;  length  of  lorica,  -j-f^  of 
an  inch.     The  male  unknown. 

Professor  Kellicott  seems  to  have  found  them  at  all  times,  though 
more  abundant  in  autumn  and  winter.  Like  others  of  the  family,  the 
female  carries  under  the  posterior  part  of  the  body  "  her  unreasonably 
large  ovum,  like  an  old-fashioned  hen's  egg."  The  case  is  so  trans- 
parent, that  it  affords  a  good  example  for  the  study  of  its  structure. 


NOTES   AND   MEMORANDA.  159 

When  under  the  compressorium  its  horns  hold  it  in  place  so  that  it 
may  be  studied  while  alive  with  high  powers. 

Trichinae. — At  a  soiree  given  at  Chicago  to  the  State  Micro- 
scopical Society  of  Illinois,  Dr.  W.  T.  Belfield  and  Mr.  H.  F.  Atwood 
showed  some  pieces  of  muscle  from  rats  fed  with  Tricliince,  on  a  warm 
stage,  with  the  worms  in  a  living  condition  moving  about.  "  It  is 
"  claimed,"  says  the  '  American  Quarterly  Microscopical  Journal,' 
"  that  this  is  the  first  time  that  living  Trichinfe  have  been  shown  in 
"  public.  The  value  of  such  exhibitions  in  arousing  a  public  interest 
"  in  scientific  studies  must  be  very  great,  and  we  trust  they  will  become 
"  more  frequent."  * 

Trichina-phobia  at  Berlin. — For  some  time  past  the  well-founded 
fear  of  trichina  has  led  to  a  microscopic  examination  of  much  of  the 
meat,  especially  pork,  sold  in  Berlin.  Eecently  the  occurrence  of  this 
pest  there  has  been  more  frequent,  and  Dr.  Luetdge,  the  Director 
of  the  Microscopic  Aquarium,  has  consented  to  give  a  course  of 
instruction  in  this  branch  of  microscopy,  which  began  on  February  17. 
The  course,  with  practical  exercises,  occupies  five  hours,  and  is  open 
to  ladies  and  gentlemen  at  the  fee  of  5s.  f  The  catalogues  of  opticians 
at  Berlin  have  long  contained  as  a  speciality,  "  Achromatic  Micro- 
scopes specially  constructed  for  Trichinae  researches,"  and  accompanied 
by  "an  illustrated  description  of  Trichina  spiralis  and  its  development." 

Organogenic  Researches  on  the  Capsule  of  Mosses  and  on  the 
Embryo  of  some  Polypodiaceae.— M.  Kienitz-Gerloff  |  has  examined 
Phascum  cuspidatum,  Ceratodon  purpureus,  Fumaria  hygrometrica,  Bar- 
hula  muralis,  Atricum  undulatum,  &c.     His  results  are  as  follows  :  — 

1st.  The  development  of  the  sporogonium  of  all  the  Bryacefe,  and 
even  of  Andrcea,  begins,  after  the  preliminary  transversal  partition 
of  the  oogonium,  by  the  formation  of  an  apical  cell ;  the  latter  origi- 
nates from  the  segmentation  produced  by  two  septa  oblique  in 
opposite  directions. 

2nd.  The  growth  of  the  summit  of  the  organ  ceases  rather  early, 
as  soon  as  the  apical  cell  is  divided  by  periclinic  §  or  longitudinal  septa. 

3rd.  Each  segment  is  divided  by  a  radial  septum  into  two 
quadrants,  inside  which  the  first  longitudinal  partitions  form  an 
endothecium  which  is  separated  from  the  surrounding  tissue  or  amphi- 
thecium;  the  endothecium  furnishes  the  columella  and  the  mother-cells 
of  the  spores ;  the  perithecium  furnishes  the  wall  of  the  sporangium. 

4th.  The  layer  of  mother-cells  originates  on  the  interior  of  the 
endothecium  by  either  primary  or  secondary  partitions  ;  in  the  former 
case  the  internal  sporiferous  sac  is  formed  after  the  layer  of  mother- 
cells  ;  in  the  latter,  at  the  same  time.  The  cells  of  the  columella 
may  be  transformed  into  a  fertile  tissue  producing  spores. 

5th  and  6th.  The  first  longitudinal  partition  which  takes  place  in 
the  amphithecium  separates  from  it  the  external  sporiferous  sac,  whose 

*  '  Amer.  Quart.  Mic.  Journ.,'  vol.  i.  (1879)  p.  167. 

t  '  Nature,'  vol.  xix.  (1879). 

X  '  Botanische  Zeitung,'  1878,  Nos.  3  and  4. 

§  That  is,  convex  in  the  same  direction  as  the  jieriphery. 


160  NOTES   AND    MEMORANDA. 

disappearance  then  creates  between  the  sporiferous  internal  sac  and 
the  wall  of  the  sijorangium  the  internal  cavity  of  the  urn,  crossed  by 
filaments  which  come  from  the  wall. 

7th.  The  peristome  belongs  by  its  origin  to  the  amphithecium. 
The  pi'imary  number  of  its  teeth  is  four,  corresponding  to  the  four 
quadrants  of  the  transversal  section,  in  which  the  radial  septa  alter- 
nate regularly  with  the  periclinic  septa. 

8th.  In  the  interior  of  the  seta  and  the  vaginula,  the  cellular  parti- 
tions follow  in  the  beginning  the  same  laws  as  the  segments  which 
are  formed  later  on ;  the  later  partitions  become  irregular,  and  trace 
inside  the  tissue  the  first  outline  of  the  central  cord. 

As  to  the  ferns,  the  author  has  studied  Pteris  serrulata,  an  As2Ji- 
dium,  Adiantum  cuneatum,  and  Gymnogramma  chrysophylla.  He  differs 
from  Hofraeister  in  that  he  considers,  in  the  quadrant  resulting  from 
the  division  of  the  oospore,  the  suspensor  of  the  embryo  as  coming 
from  one  of  the  cells  near  to  the  base  of  the  archegonium,  and  the 
root  as  emanating  from  one  of  the  cells  near  to  the  orifice.  *  He 
supposes,  moreover,  that  notwithstanding  the  fundamental  differences 
which  characterize  its  development,  the  embryo  of  the  ferns  corre- 
sponds to  that  of  the  mosses.  No  doubt  the  first  septum  is  horizontal 
in  the  oospore  of  the  mosses,  and  vertical  or  nearly  so  in  that  of  the 
ferns ;  but  in  the  opinion  of  the  author  that  would  be  owing  to  a 
torsion  of  the  embryo  of  the  ferns.  This  is  nothing  more  than  an 
hypothesis.  | 

The  "Micro-Megascope."— This  is  the  name  given  by  Dr. 
Matthews  to  an  apparatus  that  he  has  devised  for  exhibiting  objects 
(such  as  sections  of  jaws,  the  foot  of  a  frog,  insects,  &c.)  which  are 
too  large  to  be  viewed  by  the  lowest  object-glasses,  the  field  of  the 
5-inch  and  4-inch  being  respectively  only  ^^  and  y*j  of  an  inch.  They 
can  first  be  reduced  and  examined  by  the  apparatus  as  a  whole,  and 
any  portion  of  them  may  then,  by  a  readjustment  of  the  objectives,  be 
magnified  as  in  an  ordinary  Microscope.  The  object  is  placed  before 
a  large  condensing  lens  (on  the  opposite  side  being  the  source  of  light), 
and  its  image  thrown  upon  the  mirror,  or  preferably  upon  a  prism, 
the  reflected  aerial  image,  formed  by  an  objective  placed  in  the  sub- 
stage,  being  examined  by  the  object-glass  as  the  object.  By  this 
meaus  the  range  of  the  Microscope  is  extended  illimitably,  as  the 
object  can  be  placed  at  different  distances.  Dr.  Matthews  claims  that 
the  instrument  may  rank  higher  than  a  "  toy,"  though  as  a  toy  it  is 
capable  of  producing  very  novel  and  pleasing  effects.  His  attention 
was  directed  to  the  method  by  observing  the  image  formed  by  the 
areolations  in  the  valves  of  some  of  the  diatoms,  and  the  eyes  of  some 
beetles,  and  the  instrument  was  described  and  exhibited  by  him  at 
the  February  meeting  of  the  Quekett  Microscopical  Club,  and  at  the 
recent  soiree. 

*  These  ilifferences  depend  perhaps  on  the  diversity  of  the  subjects  observed. 
M.  Jonkman,  who  has  published  in  the  '  liotanische  Zeitung'  (1878),  No.  9,  a 
study  of  the  prothallus  of  Marattia,  has  represented  the  root  as  coming  from  one 
of  the  lower  cells  of  the  embryo. 

t  'Bull.  Soc.  Bot.  de  France,'  vol.  xxv.  (1878)  p.  121. 


KOTES  AND  MEMORANDA.  161 

Chlorophyll. — M.  Timiriaseff,  in  the  Keport  before  referred  to  of 
the  International  Congress  of  Botanists  at  Amsterdam,  after  some  re- 
flections on  the  various  methods  proposed  for  treating  chlorophyll 
chemically,  states  that  it  is  composed  of  two  substances,  the  one 
yellow,  xanthophyil ;  the  other  green,  the  cyanophyll  of  M.  KJraus, 
which  he  pro^wses  to  call  chlorophylline.  This  latter,  spontaneously 
decomposing,  produces  chlorophy Heine.  Chlorophylline  may  again  be 
decomposed  under  the  influence  of  light  or  mineral  acids,  and  changed 
into  what  M.  Fremy  calls  phylloxanthine.  Chloroj)hylleine  in  de- 
composing gives  phylloxanthine.* 

Professor  Haberlandt  considers  that  the  chlorophyll  in  the  coty- 
ledons of  Phasiolus  vulgaris  is  formed  from  starch.  The  starch 
granules  ai-e  gradually  surrounded  with  a  layer  of  protoplasm,  which 
is  at  first  colourless,  but  gradually  turns  green,  while  the  starch 
grains  disappear.f 

Function  of  Chlorophyll  in  the  green  Planariae. — Although 
the  presence  of  cblorophyll  has  long  been  recognized  in  the  tissues  of 
a  considerable  number  of  Invertebrata,  no  reply  has  yet  been  given 
to  the  fundamental  question  whether  it  has  the  same  function  in  the 
animal  kingdom  as  in  the  vegetable.  Can  these  animals  effect  the 
decomposition  of  carbonic  acid  under  the  influence  of  solar  light  with 
assimilation  of  the  carbon  and  disengagement  of  the  oxygen  ? 

M.  P.  Geddes  J  has  experimented  on  this  subject  at  M.  Lacaze- 
Duthiers'  Laboratory  of  Experimental  Zoology  at  Eoscoff,  where  a 
species  of  green  Planaria  was  found  in  great  abimdance,  which  had 
the  habit  of  seeking  and  exposing  itself  to  the  light  like  Hydra  viridis. 
They  were  generally  found  in  the  white  sand  in  only  a  few  centi- 
metres of  water.  Placed  in  a  small  aquarium,  they  always  sought 
the  side  of  the  light,  and  when  the  aquarium  was  exposed  to  the  sun 
their  movements  were  much  accelerated.  After  some  minutes  bubbles 
of  gas,  small  at  first,  showed  themselves  here  and  there,  augmenting  in 
number  and  volume  with  astonishing  rapidity,  equal  to  that  of  a  green 
alga  under  similar  cii'cumstances. 

The  gas  can  be  easily  collected  by  placing  the  animals  in  a  saucer, 
covered  by  another  rather  smaller  tm-ned  upside  down  under  the 
water.  At  the  end  of  the  day  the  volume  of  gas  is  sufficient  to  fill  a 
small  test-tube.  If  into  this  tube  is  plunged  a  nearly  extinguished 
match,  the  white  incandescence  is  produced  characteristic  of  diluted 
oxygen.  Ten  or  twelve  of  these  tubes  will  collect  enough  gas  to  fill 
the  long  branch  of  the  bent  tube  used  for  approximate  analyses. 
Agitation  with  the  potash  solution  shows  only  a  trace  of  carbonic 
acid,  but  with  the  addition  of  pyrogallic  acid  the  presence  of  oxygen 
is  completely  confirmed  by  the  deep  brown  colour,  and  by  the  ascent 
of  the  liquid  in  the  tube. 

A  series  of  tests  gave  43  to  52  per  cent,  of  oxygen.  A  similar 
analysis  of  atmospheric  air,  undertaken  to  ascertain  the  proportion 

*  '  Bull.  Soc.  But.  cle  France,'  vol.  sxv.  (1878)  p.  129. 
t  'Monthly  Jour,  of  Science,'  .Snl  scr.,  vol.  i.  (Ib79)  p,  204. 
X  '  Comptes  Rendus,'  vol.  Ixxxvii.  (1878)  p.  1095. 
VOL.    II.  M 


162  NOTES    AND   MEMORANDA. 

of  oxygen  lost  by  this  process,  showed  a  loss  of  5  per  cent.,  and  it 
may  therefore  be  said  that  the  gas  developed  by  these  animals 
does  not  contain  less  than  45  to  55  per  cent,  of  oxygen,  the  residue 
being  considered  nitrogen. 

It  is  easy  to  show  the  extreme  importance  of  the  action  of  light  on 
the  life  of  these  animals.  Placed  in  darkness  after  a  journey  from 
Roscoflf  to  Paris,  all  died  in  two,  three,  or  four  days,  whilst  others 
exposed  to  diffused  light  decomposed  carbonic  acid  and  survived  at 
least  two  weeks. 

Treated  with  alcohol,  the  Planariae  give  a  first  solution  of  a 
yellow  colour,  and  after  that,  but  somewhat  less  easily,  a  solution  of 
chlorophyll  of  a  magnificent  green.  The  residue  of  the  bodies  of  the 
animals,  coagulated  and  discoloured  by  alcohol,  boiled  in  water  and 
filtered,  gives  a  clear  solution  which  treated  with  iodized  water  has  the 
deep  blue  colour,  which,  disappearing  by  warming,  proves  the  presence 
of  a  considerable  quantity  of  ordinary  vegetable  starch. 

Development  and  Metamorphoses  of  Tseniae. — Thirty  years  ago 
Van  Eeueden,  Siebold,  Leuckart,  and  Kiichenmeister  established,  by 
experiments  on  carnivorous  animals,  not  only  that  the  vesicular  worms 
were  imperfect  forms  of  Ta^nife,  but  that  it  was  indispensable  that 
the  worms  should  be  swallowed  by  an  animal  to  bring  them  to  the 
perfect  state. 

This  view,  while  explaining  the  origin  of  the  armed  Tteniae  of 
carnivorous  and  some  omnivorous  animals,  did  not,  however,  explain 
that  of  the  unarmed  Tsenite  of  herbivorous  animals.  The  horse,  ox, 
sheep,  &c.,  often  have  adult  Tfenije,  and  yet  they  do  not  swallow  any 
organism  capable  of  harbouring  the  scolecides  of  their  Ttenife. 

M.  P.  Megnin  thinks  *  he  has  discovered  the  key  to  the  enigma 
from  an  examination  he  made  of  some  horses  and  rabbits.  In  these 
animals,  the  Echinococci  and  Ci/sticerci,  when  they  develop  in  the 
adventitious  cavities  in  immediate  communication  with  the  interior  of 
the  intestine  (cavities  resulting  from  the  enlargement  of  follicles  or 
glandules  into  which  the  hexacanthian  embryos  have  introduced  them- 
selves), or  even  when  they  become  free  in  the  peritoneal  cavity  of  the 
wild  rabbit,  continue  their  metamorphoses  on  the  spot,  and  arrive  at  the 
adult  state  without  quitting  the  organism  into  which  they  penetrated 
as  a  microscoinc  egg  ( •  03  to  -07  mm.  in  diameter)  either  with  the 
food  or  drink  of  the  animals.  In  this  case,  however,  they  give  rise  to 
an  unai-med  Tjeuia,  whilst  the  same  worm,  if  swallowed  by  a  car- 
nivorous or  omnivorous  animal,  would  become  in  its  intestines  an 
armed  Taenia,  that  is,  provided  with  the  hooks  of  the  scolex  from 
which  it  originates,  and  which  in  the  former  cases  it  loses. 

Some  unarmed  and  armed  Tfeniae  are  therefore  two  adult  and 
parallel  forms  of  the  same  worm,  and  the  differences,  often  very  great, 
which  they  present  (as  in  the  Tcenia  perfoliata  of  the  horse  and  the 
T.  echinococcus  or  T.  nana  of  the  dog  which  originate  from  the  same 
worm),  are  due  exclusively  to  the  difterence  of  the  habitations  in 
which  their  final  metamorphoses  are  accomplished. 

*  '  Comptes  Rendus,'  vol.  Ixxxviii.  (1879)  p.  88. 


NOTES   AND   MEMORANDA.  163 

Another  Method  of  Staining. — Dr.  A.  Lang  of  the  Zoological 
Station  at  Naples,  having  been  occupied  with  the  difficult  histology 
of  the  Turbellaria,  and  particularly  with  the  nerve-systems  of  these 
and  other  groups  of  flat  worms,  found  that  the  method  hitherto 
in  use  of  staining  the  nerve-tissues  was  not  satisfactory  in  all 
respects.  It  seemed  to  him  to  be  most  desirable  to  colour  distinctly, 
in  the  nerve-system,  not  only  the  nucleus  and  the  nucleolus,  but  also 
the  vessels  and  the  protoplasm  of  the  ganglia.  Many  Dendrocoela 
with  thick  basilar  membrane  proved  to  be  almost  totally  impervious 
to  distinct  colouring.  To  overcome  this  difficulty  he  made  several 
experiments,  and  found  the  following  mixture  (which  must  of  course 
vary  with  the  nature  of  the  object  to  be  stained)  to  be  beyond 
expectation : — 

50  parts  1  per  cent,  picro-camiine. 

50  parts  2  per  cent,  eosin  (aqueous  solution). 

The  objects,  previously  hardened  in  alcohol,  are  left  in  the 
mixture  ^  to  4  days,  according  to  their  size  and  their  facility  of 
imbibing  the  colour.  Then  comes  the  alcoholic  treatment,  which  is 
as  follows.  The  picrin  is  extracted  by  70  per  cent,  alcohol,  which 
must  be  frequently  changed.  Then  90  per  cent,  and  absolute  alcohol 
is  added,  the  latter  so  long  as  any  eosin  is  dissolved.  In  imbedding 
in  paraffin  the  copious  use  of  creasote  is  much  to  be  recommended. 

Dendrocoela  stained  in  this  way  showed,  on  making  sections,  the 
most  distinct  colouring  he  ever  obtained,  and  that  for  every  part,  but 
especially  the  nerve-system.  Nucleus  and  nucleolus,  glands,  adipose 
tissues,  &c.,  appear  nearly  carmine  red,  all  the  rest  eosin  red.* 

Size  of  Society  Screw  and  of  Slides. — At  a  recent  meeting  of 
the  State  Microscopical  Society  of  Illinois,  Mr.  Bulloch  urged  the 
desirability  of  adopting  a  uniform  objective  screw  of  larger  size  than 
the  Society  screw  now  in  use,  as  being  essential  to  the  efficacy  of  low- 
power  lenses  of  high  angle.  That  the  Society  screw  which  has  now 
become  an  almost  indispensable  convenience,  is  too  small  to  admit  of 
efficient  work  from  these  lenses,  is  (says  the  '  American  Natui'alist  f) 
a  conceded  fact,  and  some  makers  in  the  United  States  who  make  low 
powers  of  enormous  angle,  have  already  adopted  special  screws  for 
them.  The  uniformity  urged  by  Mr.  Bulloch  is  greatly  to  be  desired 
and  could  be  easily  attained  if  its  importance  were  appreciated  in 
time. 

In  an  article  upon  the  preparation  of  rocks  and  fossils  for  micro- 
scopical examination  by  E.  Fritz  Gaertner,  in  the  April  number  of 
the  '  American  Naturalist '  for  1878,  the  advantages  of  slides  measuring 
25  X  45  mm.,  over  those  3.x  1  inch,  were  stated  to  be  as  follows: — 
(1)  They  can  be  rotated  on  the  stage,  (2)  they  are  less  liable  to 
break  if  dropped,  (3)  they  take  up  less  room.  It  was  also  stated  that 
this  size  was  adopted  by  the  New  York  State  Museum  of  Natural 
History,  and  by  lithologists  and  palaeontologists  generally,  both  in 
Europe  and  America.     These  arguments  seemed  to  Mr.  S.  H.  Grage 

*  ' Zoologiseher  Anzeiger,'  vol.  ii.  p.  45. 

t  'American  Naturalist,'  vol.  xiii.  (1S79)  p.  60. 

M   2 


164  NOTES   AND   MEMORANDA. 

quite  as  valid  as  applied  to  microscopic  objects  in  general ;  and  he 
therefore  adopted  this  size  (25  X  45  mm.)  for  his  own  preparations, 
which  he  considers  have  proved  very  satisfactory  indeed.* 

The  Termination  of  the  Visceral  Arterioles  in  Mollusca. — 
Thirty  years  ago  Milne-Edwards  showed  that  in  different  parts  of  the 
body  of  molluscs  there  were  no  capillaries,  like  those  in  Vertebrata, 
establishing  a  continuity  between  the  arterial  and  venous  systems,  the 
blood  from  the  arteries  spreading  through  the  more  or  less  irregular 
spaces  called  lacunce  by  Milne-Edwards. 

In  some  molluscs  the  whole  visceral  cavity  acts  as  one  vast  lacuna, 
and  if  for  instance  Arioii  rufus  is  injected  by  one  of  the  tentacles,  the 
cavity  is  first  filled  and  then  the  whole  vascular  system. 

M.  S.  Jourdain  has  investigated  f  the  manner  by  which  the 
arterial  blood  passes  into  the  visceral  cavity  in  Arion  rufus. 

If  there  is  placed  under  the  Microscope  a  fragment  (cut  tan- 
gen  tially)  of  one  of  the  organs  contained  in  the  general  cavity,  and 
the  external  surface  is  examined  under  a  power  of  200  to  250 
diameters,  it  is  seen  that  the  final  ramifications  of  the  arteries 
(the  diameter  of  which  is  variable)  all  reach  the  free  surface  of  the 
organs,  and  that  there  they  terminate  abruptly  by  a  truncated  and 
wide-mouthed  extremity.  It  is  by  these  orifices,  nearly  always 
widely  funnel-shaped,  that  the  arterial  blood  passes  into  the  general 
cavity. 

This  curious  anatomical  disposition  seems  to  have  been  observed 
by  Alder  and  Hancock,  though  its  true  signification  escaped  them. 

M.  Jourdain  thinks  that  the  orifices  of  the  so-called  aquiferous 
vessels  of  the  Acephala  and  other  Molluscs  are  of  the  same  nature 
as  the  arterial  openings  above  described. 

Hsemocyanin  a  new  Substance  in  the  Blood  of  the  Octopus. — 
M.  L.  Fredericq  has  discovered  |  in  the  liquid  part  of  the  blood  of 
Octopus  vulgaris,  a  colourless  albuminoid  substance  which  he  calls 
haemocyanin  (at/x-a,  blood,  and  Kvavos,  blue)  as  it  forms  with  oxygen 
a  combination  of  a  deep  blue  colour.  A  vacuum,  or  contact  with  the 
living  tissues,  is  sufficient  to  drive  off  the  oxygen. 

This  substance  plays  the  same  part  in  the  respiration  of  the 
Octopus  as  haemoglobin  does  in  that  of  the  Vertebrata.  It  is  charged 
with  oxygen  in  the  branchiae  of  the  animal,  and  then  going  into  the 
arterial  system  and  the  capillaries,  it  gives  up  the  oxygen  to  the 
tissues.  The  venous  blood  is  colourless,  and  the  arterial  blood  a 
deep  blue.  These  changes  of  colour  are  clearly  due  to  the  fact  of 
respiration,  as  may  be  demonstrated  by  laying  bare  the  great  cephalic 
artery.  The  blood  is  seen  to  be  blue  while  the  animal  respires 
normally  in  the  water,  but  if  the  respiration  is  impeded  by  the  animal 
being  taken  out  of  the  water  or  by  introducing  the  fingers  into  the 
pallial   cavity,   the   arterial   blood  loses   colour   and   takes   a   pale 

*  Mr.  S.  H.  Gage,  in  '  Amer.  Quart.  Mic.  Journ.,'  vol.  i.  (1879)  p.  160. 
t  '  Comptes  Rendus,'  vol.  Ixxxviii.  (1879)  p.  186. 

X  Ibid.,  vol.  Ixxxvii.  (1878)  p.  996,  and  '  Bull.  Acad.  Eoy.  de  Belg.,' 
vol.  xlv.  (1878). 


NOTES   AND   MEMORANDA.  165 

asphyxiated  tint.  The  same  takes  place  if  the  respiratory  muscles 
are  paralyzed  by  the  section  of  the  pallial  nerves. 

Haemocyauin  appears  to  be  the  only  albuminoid  substance  in  the 
blood,  as  is  proved  by  the  method  of  successive  coagulations  by  heat. 
It  is  easy  to  isolate ;  being  the  only  colloid  substance  in  the  blood,  it 
is  sufficient  to  subject  the  plasma  of  the  blood  to  an  energetic  dialysis 
for  three  or  four  days  so  as  to  eliminate  completely  the  salts  and 
other  diffusible  substances.  The  liquid  is  then  filtered  and  evapo- 
rated at  a  low  temperature,  when  a  blue  brilliant  substance  is  obtained 
in  appearance  like  gelatine.  It  becomes  blue  in  contact  with  oxygen, 
but  colourless  in  a  vacuum  ;  coagulates  in  clots  by  heat,  alcohol,  ether, 
tannin,  the  mineral  acids,  and  the  gi'eater  part  of  the  salts  of  the  heavy 
metals.  It  burns  with  an  odour  of  burnt  horn  and  leaves  a  residue  so 
rich  in  copper,  that  the  blowpipe  at  once  establishes  its  presence. 

The  copper  seems  to  be  in  the  same  state  as  the  iron  in  haemo- 
globin and  it  plays  an  analogous  part.  Hfemogiobin  may  as  is 
known  be  decomposed  into  ferriferous  hasmatin  and  a  coagulated 
albuminoid  substance  not  containing  iron.  Haemocyanin  gives  the 
same  reaction.  M.  Fredericq  has  not  yet  been  able  to  determine 
the  proportion  of  copper  or  the  proportion  of  oxygen  with  which  it 
combines. 

Chromatic  Function  in  the  Octopus. — M.  Fredericq  also  finds  * 
that  the  changes  of  colour  in  the  skin  of  the  octopus  do  not  generally 
correspond  to  mimetic  facts,  but  might  rather  be  classed  with  the 
changes  which  the  vasomotors  produce  in  the  human  face.  They 
express  the  different  emotions,  especially  anger  or  fear. 

A  quick  movement  made  before  an  octopus  quietly  breathing  in 
the  aquarium,  renders  a  black  spot  immediately  visible  on  the  two 
extremities  of  the  pupil,  which  dilates.  The  phenomenon  disappears 
almost  as  quickly  as  it  appeared.  If  the  animal  is  excited  still 
further,  it  gets  into  a  great  fury ;  its  whole  body  assumes  a  dark 
colour,  and  the  papillfe  of  its  back  bristle  up.  These  changes  of 
colour  depend  upon  the  central  nervous  system.  The  section  of  the 
nerve  which  goes  to  the  muscles  of  the  chromatophores  is  enough  to 
paralyze  the  latter,  and  to  bring  on  the  passive  phase  of  withdrawal  of 
the  chromatophores.  That  part  of  the  skin  served  by  the  nerve 
immediately  becomes  pale,  and  then  presents  the  minimum  of  colora- 
tion. 

The  excitation  of  the  peripheral  end  of  the  nerve  cut  has  precisely 
the  contrary  effect.  In  this  case,  all  the  chromatophores  which  depend 
upon  it  are  brought  into  the  condition  of  expansion,  in  consequence  of 
the  contraction  of  the  radiating  muscles  ;  and  the  corresponding  part 
of  the  affected  surface  presents  the  maximum  of  coloration. 

Owing  to  their  superficial  situation  and  extended  distribution,  the 
pallial  nerves  are  extremely  well  adapted  for  the  demonstration  of 
these  facts. 

In  the  normal  state,  the  octopus  generally  presents  a  tint  of 
medium  intensity ;  the  dilator  muscles  of  its  chromatophores  are  in  a 

*  '  Comptes  Rendus,'  vol.  Ixxxvii.  (1878)  p.  1042. 


166  NOTES    AND    MEMORANDA. 

state  of  tonus,  or  continual  semi-tension.  This  state  gives  place  to  a 
relaxation  of  tlie  muscles  as  soon  as  the  nerves  are  cut ;  these  latter 
then  continually  transmit  to  the  periphery  a  certain  amount  of  nervous 
influence,  emanating  from  the  nervous  centres.  The  physiological 
centre  of  these  movements  of  the  muscles  of  the  chromatophores  is  in 
the  sub-oesophageal  nervous  mass,  for  the  ablation  of  the  supra- 
cesophageal  mass  does  not  produce  the  decoloration. 

The  contractility  of  the  dilator  muscles  of  the  chromatophores 
may  also  be  set  in  action  by  irritating  the  skin  (after  the  section  of 
the  nerves)  by  electricity,  heat,  or  a  di*op  of  acid,  or  by  mechanical 
friction,  which  produces  a  dark  spot. 

The  action  of  a  very  bright  light  has  an  entirely  opposite  effect ; 
it  makes  those  portions  of  the  skin  on  which  it  acts  grow  pale. 

The  dark-coloured  phase,  therefore,  represents  the  condition  of 
activity  of  the  muscles  of  the  chromatophores.  The  phase  of  de- 
coloration represents  the  passive  condition  of  withdrawal  of  the 
chromatophores. 

The  results  of  these  experiments  thus  establish  the  accuracy  of  the 
generally  admitted  conception  of  the  histological  structure  of  the 
chromatophore,  and  confirm  the  muscular  nature  of  the  radiating  fibres 
of  these  elements. 

New  Classification  of  Thallophytes. — The  classification  of  Thal- 
lophytes  recently  promulgated  by  Sachs,*  is  considered  by  Dr.  G. 
Winter  f  to  be  unsatisfactory  in  many  points.  Independently  of  minor 
details,  such  as  the  location  of  Volvox  among  Zygosporeae,  of  Characeas 
among  Carposporete,  &c.,  he  objects  to  the  main  principle  of  the 
classification,  the  abolition  of  the  hitherto  recognized  classes  of  Alga3 
and  Fungi,  and  the  establishment  in  their  place  of  four  classes  of 
Thallophytes,  each  consisting  of  a  series  containing  chlorophyll,  and 
one  destitute  of  it.  It  is  impossible  to  maintain  in  many  cases  a  near 
genetic  connection  between  groups  placed  by  Sachs  in  two  series  of 
the  same  class ;  as,  for  instance,  between  Zygnemete  and  Mucorini'; 
Vaucheria  and  Peronospora ;  Florideee  and  Ascomycetes,  &c.  Ho 
considers  the  fundamental  error,  both  in  this  classification  and  in  that 
proposed  by  Cohn,  to  consist  in  laying  too  great  stress  on  a  single 
character,  the  mode  of  reproduction,  to  the  exclusion  of  others ;  and 
proposes  to  retain  the  primary  classification  of  Thallophytes  into 
Fungi  and  Algas.  The  former  he  divides  into  Schizomycetes, 
Saccharomycetes,  Myxomycetes,  Zygomycetes,  Chytridiaceae,  and 
Oomycetes  (Basidiomycetes  and  Ascomycetes) ;  the  latter  into  Cyano- 
phyceaB,  Chlorosporeae  (including  Pandorinefe,  Conjugatfe,  Vaucheria, 
Volvocincce,  CEdogoniefB,  Coleochcete,  &c.),  Fucoideas,  and  Florideas. 
The  Basidiomycetes  are  divided  into  six  families :  —  the  Ento- 
mophthoreae  (reproduced  by  basidiospores  with  secondary  spores,  and 
gonidia  or  gemmae),  Ustilagineae  (spores  and  sporidia,  as  well  as 
conidia),  Uredineae  (teleuto-spores  and  sporidia,  as  well  as  conidia  or 
Uredo),  Tremellinefe  (basidiospores  with  sporidia,  and  spermatia  or 

*  '  Lehrbuch  del'  Botanik,'  4th  ed.,  p.  248 ;  see  also  Thiseltou-Dyer,  iu  '  Quart. 
Joum.  Micr.  Sci.,'  vol.  xv.  (1875)  p.  295. 
t  'Hedwigia,'  1871),  p.  1. 


NOTES   AND    MEMORANDA.  167 

conidia),  Hymenomycetes  (basidiospores  and  conidia),  and  Gastero- 
mycetes  (basidiospores,  and  gemmfe  or  portions  of  the  mycelium). 
While  the  Fungi  attain  their  highest  development  in  the  Ascomycetes, 
the  Algfe  pass  on,  through  Characese,  to  the  Muscinete. 

Fungoid  Diseases  of  Plants.  —  Disease  of  Chestnut  Trees. — 
M.  J.  De  Seynes  (in  continuation  of  a  paper  by  M.  J.  E.  Planchon, 
previously  published  *)  describes  a  disease  which  attacks  the  roots  of 
chestnut  trees.f  The  parasitic  mycelium,  which  is  analogous  to  that 
of  certain  Dematiei  or  Zasmidium  cellare,  forms  a  su^jerficial  network, 
and  also  one  which  penetrates  the  tissues  and  destroys  the  cellular 
layers  which  are  the  richest  in  protoi)lasm,  the  fibres  of  the  liber  and 
the  woody  fibres  not  being  attacked.  One  of  the  symptoms  of  the 
action  of  the  parasite  is  that  the  growth  of  the  young  radicles  longi- 
tudinally is  arrested,  but  the  diameter  increases,  so  that  they 
ultimately  form  olive-like  bodies,  attached  to  the  parent  branch  by 
jiedicles. 

In  a  subsequent  paper,|  M.  Planchon,  referring  to  the  doubts  he 
had  expressed  as  to  the  species  of  fungus  which  the  mycelium  which 
attacks  the  trees  gives  rise  to,  states  the  reasons  which  "  lead  him  to 
suppose  to-day  that  the  agaric  in  perspective  is  almost  certainly 
Agaricus  melleus  of  Vahl." 

Fungus^  Disease  in  Lettuces  (Peronospora  gangliiformis,  Berk.). — 
Lettuces  have  been  invaded  for  some  years,  in  France,  by  a  disease 
which  impedes  the  development  of  the  plants,  and  spots  and  dries 
up  the  leaves.  The  havoc  has  been  so  considerable  that  a  small 
body  of  market  gardeners  have  ofi'ered  a  prize  of  10,000  francs  to 
whoever  will  put  a  stop  to  it. 

M.  Max  Cornu  has  found  §  that  the  disease  is  produced  by  a 
parasitic  fungus  {Peronospora  gangliiformis,  Berk.),  which  frequently 
attacks  other  plants,  groundsel,  and  especially  the  artichoke,  where 
the  disease  is  hidden  by  the  down  of  the  leaves.  It  gives  rise  on  the 
inferior  side  of  the  leaves  to  whitish  mealy  tufts,  whence  the  popular 
name  of  "  meunier  "    (miller). 

In  tearing  off  a  strip  of  the  epidermis  of  a  lettuce  attacked,  we 
observe  conidiophorous  filaments,  issuing  through  the  opening  of  the 
stomata,  as  in  other  species  of  the  fungus.  They  are  in  groups  of 
two  or  three,  or  single ;  their  superior  jmrt  is  variously  ramified ;  the 
whole  presents  the  appearance  of  a  little  tree.  The  little  branches 
are  dilated  at  their  extremity,  and  bear  from  three  to  six  sterigmata, 
which  give  rise  to  the  conidia.  These  are  broadly  oval,  with  an  incom- 
plete papilla ;  the  germination  gives  rise  to  a  filament  sometimes 
torulose  in  a  remarkable  manner. 

The  gardeners  attribute  the  malady  to  the  west  winds,  and  to  rainy 
and  mild  weather ;  it  may  be  understood  by  this  that  these  conditions 
favour  the  dissemination  and  germination  of  the  spores  on  the  young 
plants,  for  it  cannot  be  a  question  of  spontaneous  generation. 

*  '  Comptes  Eendns,'  vol.  Ixxxvii.  (1878)  p.  583. 

t  Ibid.,  vol.  Ixxxviii.  (1879)  p.  .36. 

X  Ibid.,  p.  65. 

§  Ibid.,  vol.  Ixxxvii.  (1878)  p.  801. 


168  NOTES   AND   MEMORANDA. 

Wlieu  a  crop  of  lettuces  is  suddenly  invaded  by  Peronospora,  wBere 
must  the  cause  of  it  be  sought  ?  The  cause  ought  to  be  attributed  to 
the  surrounding  weeds,  to  the  groundsel,  artichokes,  &c.,  already 
having  the  parasite.  Sometimes,  however,  none  of  these  plants  are 
found  in  the  neighbourhood :  the  spots  are  then  produced  by  the 
germination  of  dormant  spores  or  oospores,  the  second  manner  of 
reproduction  of  the  parasite— oospores  which  germinate  after  a  long 
time  of  repose,  and  may  be  preserved  in  the  soil  or  on  its  surface, 
only  requiring  a  little  damp  and  heat  in  order  to  germinate. 

These  oospores  are  developed  in  the  tissue  occupied  by  the  filaments 
of  the  mycelium,  and  dried  up  under  its  action.  They  are  frequent 
upon  groundsel,  but  very  rarely  appear  on  the  lettuce,  although  their 
existence  there  is  most  probable. 

If  a  transversal  section  is  made  of  the  leaf  attacked,  we  see  the 
mycelium  creeping  between  the  cells,  and  putting  forth  elongated 
ovoid  suckers :  when  the  exhausted  tissue  dies  the  mycelium  dis- 
appears, and  is  itself  the  cause  of  its  death.  It  is  this  change  which 
is  met  with  during  the  summer. 

If  the  plant  is  more  completely  invaded,  the  conidiophorous  fila- 
ments are  more  rare  on  the  surface  of  the  leaf,  which  is  paler,  and  the 
leaf  dies  entirely  without  drying  up  ;  it  grows  soft,  and  turns  brownish. 
This  modification  is  generally  produced  outside  the  external  leaves ; 
and  it  is  this  which  is  found  during  the  winter. 

M.  Max  Cornu  considered  it  possible  to  find  in  the  cultivation  of 
the  plants  and  in  the  history  of  the  parasite  a  means  of  guarding 
against  its  attacks ;  and  presented  to  the  Academy  later  some  general 
considerations  on  the  subject.* 

Disease  of  the  Coffee-tree  originating  from  Anguillulce. — A  disease 
has  made  its  appearance  in  Brazil  which  rapidly  kills  the  coffee- 
tree,  an  apparently  healthy  tree  dying  within  a  week  from  its  leaves 
withering  and  falling  off."! 

On  examining  the  roots  of  the  trees  they  are  found  to  be  com- 
pletely covered  with  swellings  the  size  of  hempseed,  the  root  present- 
ing the  general  appearance  of  a  vine  attacked  by  the  Phylloxera. 
These  swellings  contain  cysts  with  hyaline  walls,  which  in  their 
development  destroy  the  fibro-vascular  structures.  Within  the  cysts 
are  a  number  of  ovules  in  all  stages  of  development ;  those  in  an 
advanced  stage  are  somewhat  reniform,  with  a  hyaline  enveloping 
membrane,  and  within  them  is  found  coiled  up  a  small  Anguillula, 
about  •  25  mm.  long,  and  without  any  trace  of  sexual  organs.  Each 
cyst  contains  from  forty  to  fifty  ovules,  or  about  30,000,000  Anguilluloe 
per  tree. 

The  animalcules,  which  are  not  reviviscent,  when  developed 
escape  out  of  the  cyst,  leaving  the  cavity  open,  and  the  roots  soon  rot 
and  are  invaded  by  cryj)togams.} 

*  'Comptes  Eenchis,'  vol.  Ixxxvii.  (1878). 

t  M.  C.  Jobert,  in  'Comptes  Rendus,'  vol.  Ixxxvii.  (1878)  p.  941. 

X  See  also  a  paper  by  the  Rev.  R.  Abbay,  on  "  Hcmilcia  vastatrix,  the  eo-called 
Coftee-leaf  Disease  of  Ceylon,"  in  'Jour.  Linn.  Soc'  (Bot.),  vol.  xvii.  (1878) 
p.  173. 


NOTES   AND  MEMORANDA.  169 

Organization  of  Hygrocrocis  arsenicus,  Breb. — This  cryptogam 
was  gathered  for  the  first  time  in  1836,  and  presented  to  tlie  '  Academie 
des  Sciences '  by  Bory  Saint- Vincent,  who  referred  it  to  the  genera 
Hygrocrocis  or  Leptomitus,  which  de  Brebisson  confirmed  by  naming 
it  Hygrocrocis  arsenicus.  In  1841  Louyet  foand  it  again  in  Belgium. 
Since  then,  although  all  druggists  might  have  seen  it  in  their  bottles 
of  arsenical  preparations,  it  has  not  attracted  any  attention. 

M.  L.  Marchand  has  recently  studied  it  as  developed  in  "  Fowler's 
solution,"  and  thus  describes  it:* — The  invasion  of  the  solution 
commences  as  an  opaline  cloudiness  in  suspension  in  the  liquid. 
This  cloudiness,  examined  under  the  Microscope,  presents  the  appear- 
ance of  a  glairy  mass  containing  brilliant  points,  fine  dust,  whose 
particles  are  so  minute  that  they  cannot  be  measured. 

Later  on,  the  spot  increases  and  becomes'  coloured  in  the  centre. 
The  periphery  remains  glair j,  but  the  centre  (the  oldest  part)  shows 
globules  in  tubes,  whose  walls,  with  age,  become  less  xmdecided. 
These  tubes  are  ramified,  and  then  their  contents  become  homo- 
geneous. In  proportion  to  their  age  the  formation  of  septa  takes 
place.  The  septa,  at  first  widely  separated,  approach  each  other  in 
such  a  manner  that  the  dimensions  of  the  cells  become  equal  in  all 
directions. 

At  first  the  mass  remains  opaline  and  floating  in  the  liquid  if  the 
bottle  has  not  been  shaken;  later  on  the  cloudiness  becomes  dark 
towards  the  centre,  and  at  last  presents  a  brownish  point,  which 
increases  and  reaches  the  periphery ;  the  opaline  portions  are  invaded, 
and  the  mass,  become  brown,  is  precipitated  at  the  bottom  of  the 
bottle.  Examined  under  a  low  power,  it  resembles  a  little  chest- 
nut from  1  to  3  mm.  in  diameter,  bristling  with  points.  These 
points  are  the  extremities  of  filaments,  which  for  the  most  part 
have  become  torulose,  knobbed  and  irregular,  and  some  moniliform. 
From  their  protuberances  start  fresh  filaments  which  ramify,  or  little 
blisters,  which  are  hyaline  and  pyriform.  The  mass  becomes  more 
and  more  brown,  and  at  last  completely  black ;  the  plant  is  now  in 
fructification. 

If  the  elements  which  compose  it  are  examined  at  this  stage  we 
find— 

1st.  That  the  filaments  of  the  periphery  are  elongated  inordi- 
nately into  hyaline  tubes,  which  terminate  in  a  glairy  mass,  which 
envelops  the  organism  and  forms  a  cloudiness  round  it  which  re- 
sembles the  cloudiness  which  first  appeared;  in  this  network  and 
glairy  mass  float  spores,  and  the  debris  of  various  organs. 

2nd.  That  all  the  filaments  of  the  centre  have  assumed  new  forms. 
The  torulose  moniliform  filaments  have  increased  and  become  almost 
entirely  black.  It  is  impossible  henceforth  to  see  their  contents ; 
they  disarticulate  with  extreme  facility,  and  the  knobbed  irregular 
filaments  disarticulate  with  the  same  facility.  They  are  less  dark  in 
colour,  but  the  pyriform  blisters  which  they  have  formed  have  become 
sporangioles  of  a  very  dark  hue,  particularly  on  the  side  of  the  point 
which  attaches  them  to  the  filament ;  at  their  opposite  part,  which  is 
*  '  Comptes  Reudus,'  vol.  Ixxxvii.  (1878)  p.  761. 


170  NOTES    AND   MEMORANDA. 

BWoUen,  they  open  by  a  dehiscence  into  two  lips,  and  from  each 
escapes  from  two  to  three  colourless  hyaline  spores,  evidently  pro- 
vided with  a  membrane.  The  extremities  of  these  same  filaments, 
which  have  remained  regular,  and  whoso  cells  are  rectangular,  and 
more  or  less  elongated,  terminate  by  bunches  of  spores,  some  rounded 
and  arranged  in  umbellated  rows  around  the  supei'ior  cell ;  others, 
elongated  into  rods  which  become  smaller  and  smaller  in  proportion 
as  we  ajiproach  the  extremities,  are  in  ramified  bunches.  Both 
resemble  Spicaria. 

We  ought  perhaps  to  class  among  the  means  of  reproduction  some 
bodies  met  with  in  fewer  number  than  the  preceding  :  they  are 
larger  than  the  spores  of  the  sporangiolos,  are  reticulated  on  the 
surface,  and  marked  with  a  star,  generally  with  three  points ;  most 
often  they  are  found  free ;  in  one  case  one  of  them  seemed  to  be 
carried  by  a  filament,  and  it  seemed  embraced  at  its  base  by  two 
branches  which  were  curved  towards  it. 

M.  Marchand  draws  the  conclusion  that  Hygrocrocis  arsenicus, 
formerly  placed  amongst  the  Algte,  is  a  fungus  belonging  to  the 
Dematiei ;  a  practical  confirmation  of  opinions  given  a  priori  by 
Decaisne,  Bornet,  Van  Tieghem,  &c. 

|The  "Plastids"  of  the  lower  Plants.— M.  E.  Hallier  has  published 
a  book  on  this  subject,  in  which  he  deals  with  the  parasitic  diseases 
which  attack  the  potato  and  the  cabbage  butterfly.  The  author 
dwells  at  length  on  Peronospora,  which  in  his  opinion  is  not  a  real 
parasite,  but  a  saprophyte.  He  asserts  that  he  has  seen  Bacteria  and 
Vibriones  originate  from  the  plastids  of  Peronospora.  He  gives  the 
name  of  plastids  to  the  accumulations  of  protoplasm  which  are  formed 
not  only  in  the  conidia,  but  also  in  the  interior  of  the  mycelium  of 
this  cryptogam.  In  his  opinion  the  contagious  character  of  the 
disease,  and  the  cause  of  the  alterations,  are  to  be  found  in  the  ex- 
istence of  these  agents  of  putrefaction,  Bacteria  or  Vibriones.  He 
has  also  studied  another  disease  of  the  potato,  which  he  thinks  is  due 
to  Pleospora  pohjlricha,  Tub,  although  he  has  not  proved  by  actual 
exjjeriment  that  it  is  actually  this  Pleospora,  a  j)arasite  on  grasses, 
and  moreover  rare  in  Germany,  which  penetrates  into  the  soil  and 
thence  into  the  tubercules  of  the  potato  to  cause  this  disease.  A  very 
common  Lejiidoptera,  Pieris  Brassicce,  is  attacked  by  two  diseases,  a 
kind  of  mnscardine,  and  a  kind  of  gattine.  The  former  is  contagious, 
and  is  apparently  reproduced  by  the  conidia  arising  at  the  extremity 
of  the  filaments  which  have  passed  through  the  body  of  the  insect. 
The  second  is  caused  by  one  of  the  Torulacei,  and  the  author  thinks 
that  here  again  the  contagion  and  disorders  are  not  due  directly  to 
the  joints  of  Arthrococcus,  but  to  Micrococci  developed  in  the  plastids 
of  this  Arthrococcus.  * 

Staining  for  Fungi. — Dr.  W.  Hassloch  has  obtained  excellent 
results  in  the  examination  of  fungi  by  using  gold  chloride  as  a  stain- 
ing fluid.     He  employed  a  one-half  per  cent,  solution,  which  stains 

*  '  IJull.  Soc.  Bot.  de  Fraucu,'  vol.  xxv.  (1878)  p.  G6. 


NOTES   AND   MEMOBANDA.  171 

in  from  one  to  six  hours,  and  the  specimens  were  mounted  in  diluted 
glycerine.* 

Spines  of  Echini. — The  last  published  part  of  the  '  Transactions 
of  the  Eoyal  Ii-ish  Academy '  f  contains  a  memoir  by  Mr.  H.  W. 
Macintosh,  B.A.,  on  the  structure  of  the  spines  in  the  sub-order 
of  the  Desmosticha  (Haeckel).  In  indicating  four  series  into  which, 
judging  from  the  structure  of  the  spines,  this  sub-order  may  be 
divided,  the  author  expresses  his  opinion  that  the  characters  derived 
from  the  spines  are  just  as  useful  as  any  other  characters  di-awn  from 
the  comparison  of  individual  parts.  He  finds  it  just  as  easy  and  as 
certain  to  recognize  a  Diadema,  an  Echinus,  or  an  Arbacia  by  the 
structure  of  its  spines,  as  by  the  arrangement  of  its  pores  or  the 
disposition  of  its  anal  or  genital  plates.  The  paper  is  accom- 
panied by  three  plates  containing  twenty-seven  figures,  all  drawn 
by  the  author  with  the  assistance  of  a  Wollaston's  camera  lucida. 
The  figures  represent  transverse  sections  of  primary  inter-ambulacral 
spines  of  some  twenty-six  species,  and  have  been  drawn  on  stone  by 
Tuffen  West  with  great  care  and  accuracy  .| 

The  Locomotor  System  of  Medusae. — Mr.  G.  J.  Eomanes  has  con- 
cluded his  observations  on  this  subject,  which  were  commimicated  to 
the  Eoyal  Society  in  a  paper  read  in  January  last.§ 

The  principal  bulk  of  the  paper  is  devoted  to  a  full  consideration 
of  numerous  facts  and  inferences  relating  to  the  phenomena  of  what 
the  author  calls  "  artificial  rhythm."  Some  of  these  facts  have  already 
been  published  in  abstract,  ||  and  to  explain  those  which  have  not  been 
published  would  involve  more  space  than  it  is  here  desirable  to  allow. 
The  tendency  of  the  whole  research  on  artificial  rhythm,  as  produced 
in  various  species  of  Medusfe,  is  to  show  that  the  natural  rhythm  of 
these  animals  (and  so  probably  of  ganglio-muscular  tissues  in  general) 
is  due,  not  exclusively  to  the  intermittent  natui'e  of  the  ganglionic 
discharge,  but  also  in  large  measure  to  an  alternate  process  of 
exhaustion  and  restoration  of  excitability  on  the  part  of  the  respond- 
ing tissues — the  ganglionic  period  coinciding  with  that  during  which 
the  process  of  restoration  lasts,  and  the  ganglionic  discharge  being 
thus  always  thrown  in  at  the  moment  when  the  excitability  of  the 
responding  tissues  is  at  its  climax. 

Light  has  been  found  to  stimulate  the  lithocysts  of  covered-eyed 
Medusae  into  increased  activity,  thus  proving  that  these  organs,  like 
the  marginal  bodies  of  the  naked-eyed  Medusae,  are  rudimentary  organs 
of  vision. 

The  polypite  of  Aurelia  aurita  has  been  proved  to  execute  move- 
ments of  localization  of  stimuli  somewhat  similar  to  those  which  the 
author  has  already  descriljed  as  being  performed  by  the  polypite  of 
Tiaropsis  indicans. 

Alternating  the  direction  of  the  constant  current  in  the  muscular 

*  '  New  York  Medical  Jour.,'  Nov.  1878. 

t  Vol.  xxvi.  (Science),  Part  17. 

X  '  Nature,'  vol.  xix.  (1879)  p.  319. 

§  'Proc.  Ko}'.  Soc.,'  vol.  xxviii.  (1879)  p.  266. 

II  '  Proc.  Hoy.  Soc.,'  vol.  xxv.  p.  226. 


172  NOTES   AND    MEMORANDA. 

tissues  of  the  Medusaa  has  the  eflfect  of  maintaining  the  make  and 
break  stimulations  at  their  maximum  value ;  but  the  value  of  these 
stimulations  raj^idly  declines  if  they  are  successively  repeated  with 
the  current  passing  in  the  same  direction. 

In  the  sub-umbrella  of  the  MedusaB  waves  of  nervous  excitation 
are  sometimes  able  to  pass  when  waves  of  muscular  contraction  have 
become  blocked  by  the  severity  of  overlapping  sections. 

J^xhaustion  of  the  sub-umbrella  tissues — esi)ecially  in  narrow  con- 
necting isthmuses  of  tissue — may  have  the  effect  of  blocking  the 
passage  of  contractile  waves, 

Lithocysts  have  been  proved  sometimes  to  exert  their  ganglionic 
influence  at  comparatively  great  distances  from  their  own  seats — ^con- 
tractile  waves  originating  at  points  in  the  sub-umbrella  tissue  remote 
from  a  lithocyst,  and  ceasing  to  originate  at  that  j^oint  when  the 
lithocyst  is  removed.  A  nervous  connection  of  tliis  kind  may  be 
maintained  between  a  lithocyst  and  the  point  at  which  the  waves  of 
contraction  originate  even  after  severe  forms  of  section  have  been  inter- 
j)osed  between  the  lithocyst  and  that  point. 

When  the  sub-umbrella  tissue  of  Aurelia  is  cut  throughout  its 
whole  diameter,  the  incision  will  again  heal  up,  sufficiently  to  restore 
physiological  continuity,  in  from  four  to  eight  hours. 

Tetrapteron  volitans. — This  peculiar  marine  hydrozoon  was  im- 
perfectly described  in  1851  by  M.  Busch,  who  named  it  Tetraplatia 
volitans.  It  has  now  been  re-discovered  by  Professor  C.  Claus,  who 
gives  it  the  name  at  the  head  of  this  paragraph.* 

The  animal  in  the  extended  condition  is  of  an  elongated  pear- 
shape,  but  four-sided  instead  of  circular  in  section  ;  the  smaller  end 
bears  the  oral  aperture,  and  answers  to  the  manubrium  of  a  medusa, 
the  larger  or  aboral  end  answering  to  the  bell.  At  the  middle  (that  is, 
half-way  between  the  oral  and  aboral  poles)  of  each  of  the  four  faces  is 
a  depression,  from  which  springs  a  bilobed  wing-like  appendage,  pro- 
vided with  muscles,  by  the  flapping  of  which  the  animal  is  propelled 
through  the  water,  with  the  aboral  pole  forwards.  In  each  division 
of  each  wing  is  an  otolithic  sac.  The  mouth  leads  into  an  enteric 
cavity,  which  is  continued  into  the  aboral  portion  of  the  hydrosoma. 
Reproductive  organs  occur  as  four  masses,  probably  ectodermal  pro- 
ducts, in  the  four  longitudinal  edges  of  the  body. 

The  ectoderm  consists  of  large  ciliated  cells,  some  of  which  con- 
tain thread-cells,  while  in  others  the  protoplasm  is  so  modified  as  to 
form  a  gland,  presenting  a  distinct  aperture,  and  a  radiating  arrange- 
ment of  the  glandular  contents.  The  endoderm  cells  are  so  extensively 
vacuolated  as  to  form  a  mere  network  of  plasma-threads.  The  vacuoles 
probably  contain  the  albuminoid  products  of  digestion  ;  in  some  of 
them  small  aggregations  of  crystalline  rods  are  found,  probably  the 
final  products  of  urinary  metabolism.  Amongst  these  vacuolated  cells 
smaller  granular  endoderm  cells  occm-  at  intervals,  two  or  three 
together. 

Between  the  ectoderm  and  endoderm  is  a  structureless  connective 

*  '  Aivhiv  f.  Mikr.  Anat.,'  vol.  xv.  (1878)  p.  8i9. 


NOTES   AND   MEMORANDA.  173 

lamella  or  supporting  layer  (Stiitzlamella)  ;  it  is  very  thick  in  the 
wings,  and  serves  for  the  attachment  of  the  muscles. 

The  author  concludes  with  a  discussion  of  the  affinities  of  Tetra- 
pteron,  which  he  considers  to  hold  an  intermediate  place  between 
Polypes  and  Medusas. 

The  Algae  of  the  "White  Sea.  —  This  paper,  by  Dr.  C.  Gobi, 
in  the  Memoirs  of  the  St.  Petersburg  Academy,*  is  the  first  detailed 
account  of  the  algfe  of  the  White  Sea.  The  species  are  principally 
those  found  throughout  the  Arctic  Ocean ;  but  Dr.  Gobi  remarks  that 
the  vegetation  of  the  southern  part  of  the  White  Sea  has  a  more 
northern  character  than  that  of  the  northern  part,  which  is  explained 
by  the  statement  that  many  forms  of  Western  Europe  which  make  their 
way  to  the  northern  part  do  not  extend  to  the  southern  part.  Dr.  Gobi 
unites  a  considerable  number  of  species  considered  by  Agardh  and 
others  to  be  distinct,  even  regarding  Bliodomela  lycopodioides  as  a 
form  of  B,.  suhfusca  and  PolijsipJionia  arctica  as  a  variety  of  P.  varie- 
gata.  Bhodophyllis  veprecula,  Ag.,  is  referred  to  It.  dichotoma,  Le- 
pechin.  The  new  species  and  varieties  observed  and  studied  by  Dr. 
Gobi  amount  to  nine,  and  the  total  number  of  species  gathered  to 
seventy-six. 

The  paper  contains  valuable  references  to  the  species  of  Euprecht 
in  the  Academy's  herbarium. 

Achromatic  Lenses. — Mr.  E.  M.  T.  Tydeman,  of  Liverpool,  has  ob- 
tained provisional  protection  for  an  invention  which  we  describe  nearly 
in  his  own  words,  as  appearing  in  the  printed  specification: — "My 
invention  consists  of  improvements  in  the  construction  of  compound 
achromatic  lenses  suitable  for  use  in  Microscopes  and  other  optical 
instruments,  and  is  intended  more  completely  to  eliminate  the  large 
irrationality  or  want  of  correspondence  between  the  coloured  spaces  in 
the  various  spectra  (secondary  spectrum),  and  to  render  the  lenses  more 
perfectly  achromatic.  It  consists  in  forming  the  lenses,  not  as  hitherto 
by  the  union  of  lenses  made  of  different  kinds  or  species  of  glass  or 
other  refractive  media,  but  of  one  kind  or  species  only,  yet  of  different 
densities  and  refractive  powers,  in  which  the  irrationality  or  unequal 
refraction  of  the  coloured  rays  is  not  so  great.  I  therefore  construct 
my  improved  achromatic  lenses  with  two  or  more  glasses  made  from 
material  of  the  same  kind  or  species  of  glass  (such  as  that  known  as 
flint  glass,  which  is  capable  of  being  made  of  varying  density),  but  of 
different  densities  or  refractive  indices;  and  I  also  use  flint  glass 
lenses  in  lieu  of  the  usual  crown  or  plate  glass  lenses  in  achromatic 
object-lenses.  For  a  Microscope  object-glass — often  composed  of  two 
or  more  approximately  achromatic  lenses,  or  set  of  lenses,  either  in 
contact  or  nearly  in  contact — I  sometimes  make  one  of  the  several  sets 
of  compound  lenses  of  one  refracting  medium,  such  as  flint  glass,  and 
the  other  set  or  sets,  or  single  lenses,  of  a  different  refracting  medium 
or  media,  or  I  use  single  lenses  of  crown,  or  flint,  or  any  other 
substance  in  combination,  though  not  necessarily  in  contact  with  an 

*  'Mem.  Imp.  Acad.  Sc.  St.  Petersburg,'  vol.  xxvi.  (1878);  'Amer.  Jour.  Sci. 
and  Arts,'  ser.  3,  vol.  xvii.  (1879)  p.  71. 


174  NOTES   AND   MEMORANDA. 

achromatic  set  composed  wholly  of  flint  glass  or  any  other  suitable 
refracting  substance." 

In  connection  with  this  subject,  we  may  refer  to  a  paper  read  by 
Professor  Stokes  at  theEoyal  Society,*  in  which  he  describes  an  easy, 
and  at  the  same  time  accurate,  method  of  determining  the  ratio  of  the 
dispersions  of  glasses  intended  for  objectives — a  method  depending  on 
the  achromatizing  of  one  prism  by  another. 

Development  of  Spongilla  fluviatilis. — Professor  Ganin,  of  War- 
saw, has  undertaken  some  investigations  to  decide  the  following  mor- 
phological questions: — Does  the  gastrula  stage  exist  in  the  develop- 
mental history  of  Spongilla  f  and  if  it  exists,  what  is  its  ontogenetic 
significance?  In  what  way  are  the  germ-layers  formed,  and  in  what 
relation  do  they  stand  to  the  adult  structures  of  the  sponge  ?  Does 
the  so-called  syncytium  of  Haeckel  exist  in  Spongilla  ?  Is  the  ento- 
derm in  sponges  confined  to  the  so-called  ciliated  chambers  and 
their  homologues  (radial  tubes  of  the  Sycones)  ? 

In  opposition  to  Haeckel's  views  on  this  last  question,  it  is  stated 
by  F.  E.  Schulze,  Barrois,  and  Metschnikof,  that  the  ciliated  chambers 
(radial  tubes)  do  not  open  into  the  digestive  cavities,  but  into  cavities 
or  canals  which  are  lined  with  a  continuation  of  the  ectoderm.  If 
this  last  view  of  the  morphological  import  of  the  internal  cavities 
of  sponges  is  correct,  the  homology  of  their  canal  system  with  the 
gastro-vascular  system  of  the  Coelenterata  disappears,  and  the  place  of 
sponges  in  the  latter  group  has  still  to  be  demonstrated. 

The  answer  to  all  these  questions  will  be  found  in  the  author's 
forthcoming  work,  '  Contributions  to  the  Anatomy  and  Developmental 
History  of  Sponges,'  of  which  the  following  is  a  brief  summary  of  the 
more  important  results. 

The  ovum  of  Spongilla  undergoes  a  complete  segmentation  into 
equal-sized  blastomeres,  a  solid  globular  mass  of  cells — the  so-called 
morula — being  produced.  The  peripheral  cells  of  the  embryo  then 
begin  to  multiply  more  quickly,  and  thus  become  distinguished  from 
the  larger  and  darker  cells  of  the  inner  mass.  In  this  way  the  two 
primary  germ-membranes,  the  (primitive)  ectoderm  and  entoderm,  are 
differentiated  from  each  other.  Simultaneously  with  the  commence- 
ment of  this  separation,  a  cavity  is  hollowed  out  in  the  interior  of  the 
central  mass  of  entoderm,  as  the  result  of  the  disaggregation  and 
dissolution  of  its  cells.  This  gastric  cavity  never  opens  during  the 
whole  period  of  embryonic  development,  or  during  the  free  existence  of 
the  larva.  The  morula  stage  passes  first  into  the  so-called  plano-gastrula 
or  planula  stage — a  larva  of  regular  oval  form,  with  large  internal 
cavity,  and  without  any  external  opening.  The  inner  series  of  the  cells 
of  the  primitive  thick  entoderm  mass  alter  their  form  and  structui-e 
at  an  early  period,  and  become  the  actual  entoderm  of  the  adult.  The 
remainder  of  the  entoderm  mass  forms  the  mesoderm  of  the  larva. 
This  consists  of  several  rows  of  dark  granular  cells,  filled  with  rounded 
yolk-spheres.  The  spiculae  of  the  skeleton  begin  to  develop  very 
early  in  the  interior  of  the  mesoderm  cells.     The  body  of  the  ovoid 

*  'Proc.  Roy.  Soc.,'  vol.  xxvii.  (1878)  p.  485. 


NOTES   AND   MEMORANDA.  175 

free-swimming  larva  thus  consists  of  tliree  different  germ-lamellre. 
The  ectoderm  is  formed  of  a  series  of  flagellate  cylinder-cells.  The 
mesoderm  is  a  much  thicker  mass,  consisting  of  rounded  amoeboid 
cells.  The  entoderm  is  formed  of  a  single  row  of  transparent  flat 
polygonal  cells.  At  the  posterior  narrow  pole  of  the  larva  an 
accumulation  of  the  mesoderm  cells  takes  place  at  an  early  period, 
and  occupies  nearly  a  third  or  a  half  of  the  length  of  the  lai'va. 
In  the  anterior  clear  part  of  the  larva  there  is  found  a  large 
gastric  cavity.  The  skeleton  is  confined  to  the  posterior  dark  part 
of  the  larva.  On  the  external  surface  of  the  free-swimming  larva 
are  seen  a  number  of  ectodermal  processes,  of  different  shapes  and 
sizes,  which  are  of  no  morphological  signification.  Between  the 
ectoderm  and  mesoderm  of  the  larva  is  seen  a  clear  interval,  into 
which  the  processes  of  the  mesoderm  cells  project  in  many  places, 
and  which  is  to  be  regarded  as  the  body-cavity.  The  posterior  mass 
of  mesoderm  grows  forwards,  as  a  result  of  which  the  stomach-cavity 
becomes  very  much  narrowed.  The  larva  fixes  itself  by  means  of  the 
ectoderm  cells  of  its  posterior  half,  and  soon  loses  its  original  form 
and  assumes  a  flat  discoid  shape.  Transverse  sections  of  the  body  of 
the  larva  in  such  very  early  stages  of  the  metamorphosis,  prove  that 
the  at  first  simple  gastric  cavity  does  not  disappear,  although  it  is 
much  altered  by  the  great  increase  of  the  mesoderm,  but  passes  imme- 
diately into  the  entodermal  cavity  of  the  adult  S'pongilla,  Very  soon 
after  the  larva  becomes  fixed,  a  number  of  the  so-called  ciliated 
chambers  make  their  appearance  simultaneously  at  several  points  in 
the  mesoderm  ;  their  development  depends  upon  out-pushings  of  the 
entoderm.  The  histological  differentiation  of  these  ciliated  chambers, 
which  at  first  are  covered  with  flat  cells,  takes  place  somewhat  later, 
after  the  first  central  opening  of  the  young  Spongilla  has  been  formed. 
This  first  opening,  which  must  be  regarded  as  the  oral  aperture,  is  not 
formed  by  invagination  of  the  ectoderm  ( Barrels),  but  by  a  breaking 
through  of  the  mesoderm  and  entoderm  cells  on  the  upper  walls  of  the 
stomach-cavity.  The  oral  orifice  of  Spongilla  differs  from  that  of 
other  animals  in  that  it  does  not  open  externally  directly,  but  into  a 
special  cavity,  which  is  to  be  considered  as  the  body-cavity.  The 
ectoderm  and  entoderm  are  always  separate  in  Spongilla  ;  the  margins 
of  the  oral  aperture  do  not  become  fused  with  the  ectoderm.  Soon 
after  the  formation  of  the  oral  orifice,  some  of  the  so-called  "  ingestivo 
aijertures"  make  their  appearance.  In  the  matter  of  development, 
structure,  and  relation  to  other  parts,  these  structures  are  perfectly 
homologous  with  the  oral  aperture. 

The  further  development  of  the  young  Spongilla  depends  upon  the 
increase  of  the  histological  elements  of  the  three  membranes,  in  such 
a  way  that  each  membrane  gives  rise  only  to  elements  of  the  same 
morphological  significance.  The  formation  of  the  ciliated  chambers 
by  division  or  by  budding  of  old  already-formed  chambers,  I  have 
never  seen.  The  so-called  osculum  is  homologous,  as  its  development 
shows,  to  the  porus  dermalis.  It  consists  of  two  layers  only  (meso- 
derm and  ectoderm).  The  full-grown  Spongilla  is  formed  of  three 
different  membranes,  which  originate  directly  from  those  of  the  same 


176  NOTES   AND  MEMORANDA. 

name  in  the  larva.  From  the  ectoderm  of  the  larva  is  formed  the 
external  layer  of  the  skin,  which  in  Spongtlla  consists  of  two  distinct 
layers,  the  epidermis  and  cutis.  The  larval  entoderm  forms  the  thin 
single-layered  lining  of  all  internal  cavities  or  canals  (the  body-cavity 
excepted),  as  well  as  a  covering  to  the  mesodermal  septfe,  trabeculje, 
&c.  The  mesoderm  of  Spongilla  may  be  regarded  as  a  simj^le  form  of 
connective  tissue  in  which  the  cell  element  prevails,  and  the  structure- 
less gelatinous  matrix  is  very  slightly  developed.  A  syncytium,  in 
Haeckel's  sense,  does  not  exist  in  the  Spongilla.  Fusion  of  Spongillce 
of  dififerent  forms  and  sizes  never  gives  rise  to  the  formation  of  the 
so  called  pseudo-oral  orifices,  pseudo-enteric  cavities,  communicating 
canals,  and  other  cavities  coated  with  ectoderm. 

We  can  distinguish  in  sponges  two  different  modes  of  development. 
One  group  of  sponges  show  in  their  developmental  history  a  well- 
pronounced  blastula  stage,  i.  e.  a  hollow  single-layered  sac  with  a  largo 
segmentation  cavity  in  the  interior.  Some  of  those  sponges,  as 
Halisarca  lob^daris,  Dujardinti,  Ascetta  primordialis,  A.  claihrus,  have 
an  archiblastula  stage  ;  in  others  of  the  same  group  (Sycandra  raphanus, 
compressa,  the  calcareous  sponges  of  Barrois),  the  modified  amphihlas- 
tula  form  obtained.  In  this  form  of  the  generation  cycle  the  two 
primitive  embryonic  membranes  originate  by  the  cells  of  the  posterior 
half  of  the  sac  undergoing  differentiation  into  the  primitive  entoderm, 
whilst  the  cells  of  the  other  half  of  the  blastula  give  rise  to  the  ecto- 
derm of  the  larva.  The  formation  of  the  gastric  cavity  in  this  case 
depends,  in  all  probability  (as  F.  E.  Schultze  and  Barrois  have 
already  noticed),  upon  the  invagination  of  the  posteriorly-situated 
entoderm,  in  the  interior  of  the  segmentation  cavity  of  the  embryo. 
But  whether  the  aperture  of  invagination  of  this  provisional  archi- 
gastrula  passes  directly  into  the  actual  oral  orifice  of  the  sponge, 
remains  to  be  proved.  The  sponges  of  the  second  group  begin  their 
ontogeny  with  the  morula  stage  (all  siliceous  sponges — Spongilla, 
Esperia,  Beniera,  Amorphian,  Desmocidon,  Isodictia,  Raspailia  ;  also  the 
calcareous  sjionges  of  Haeckel).  The  formation  of  all  three  embryonal 
membranes  depends  in  this  case  on  the  delamination  process.  The 
stomach  cavity  of  the  larva  is  formed  by  the  separation  and  dissolution 
of  some  cells  of  the  interior  of  the  entoderm  mass.  In  place  of  the 
gastrula,  the  plano-gastrula  makes  its  appearance.  The  generation 
cycle  with  the  blastula  stage  is  to  be  regarded  as  the  most  simple.  To 
this  corresponds  also  the  much  simpler  organization  of  the  sponges 
of  this  group  :  Halisarca,  for  example,  has  no  skeleton,  is  everywhere 
covered  with  the  ectoderm  of  the  larva,  &c.  The  sponges  which  in  their 
developmental  history  pass  through  the  morula  stage,  are  also  more 
complicated  in  morphological  and  histological  respects.  The  place 
of  the  sponges  as  a  particular  class  of  the  Coelenterata  is  entirely 
natural,  on  the  ground  of  all  the  facts  hitherto  known  of  comparative 
anatomy  and  embryology.* 

Mr.  F.  M.  Balfour  refers  shortly  to  the  above  in  the  article  next 
mentioned,  and  considers  that  M.  Ganin's  account  of  the  development 
of  Spongilla  is  not  reconcilable  with  that  of  Sycandra,  as  described 
*  '  Zoologischcr  Anzcigcr,'  vol.  i.  (1878)  p.  195. 


NOTES   AND   MEMOKANDA.  177 

by  Professor  Schulzo,  and  tliat,  "  considering  the  diflficulties  of  obser- 
vation, it  appears  better  to  assume  for  tliis  and  some  other  descriptions 
that  the  observations  are  in  error  rather  than  that  there  is  a  funda- 
mental want  of  uniformity  in  development  amongst  the  Spongida." 
It  would  be  superfluous  for  us  to  lay  stress  on  the  value  of  Mr. 
Balfoui-'s  opinion  on  such  a  matter  as  this. 

Morphology  and  Systematic  Position  of  the  Spongida.  —In  an 
article  in  the  '  Quarterly  Journal  of  Microscopical  Science,'  *  Mr. 
Balfour  points  out  that  Schultze's  last  memoir  f  on  the  development 
of  Calcareous  Sponges  confirms  and  enlarges  Metschnikoff's  earlier 
observations,  |  and  gives  us  at  last  a  fairly  complete  history  of  the 
development  of  one  form  of  calcareous  sponge ;  and  the  facts  thus 
established  have  suggested  to  him  a  view  of  the  morphology  and 
systematic  position  of  the  Spongida  somewhat  different  to  that  now 
usually  entertained,  though  it  does  not  claim  to  be  more  than  a  mere 
suggestion,  which,  if  it  serves  no  other  function,  may  perhaps  be  of 
use  in  stimulating  research. 

After  a  brief  statement  of  the  facts  which  may  be  considered  as 
established  with  reference  to  the  development  of  Sycandra  rapJianus, 
the  form  which  was  studied  by  both  Metschnikoff  and  Schulze, 
Mr.  Balfour  says  that  he  thinks  that  the  larva  represents  an  ancestral 
type  of  the  Spongida,  consisting  of  a  colony  of  Protozoa,  one-half 
differentiated  into  nutritive,  and  the  other  into  locomotor  and 
respiratory  forms,  thus  constituting  a  link  between  the  Protozoa  and 
Metazoa.  He  accounts  for  the  ciliated  cells  becoming  invaginated  to 
form  part  of  the  lining  of  the  gastrula  cavity,  by  supposin'4'  that  on 
the  ancestral  sponge  becoming  fixed  the  locomotive  ciliated  cells 
increased  in  size  and  number  less  than  the  nutritive,  and  so  came  to 
line  the  cavity  of  the  gastrula,  some  of  the  nutritive  subsequently 
passing  in  at  its  mouth.  In  the  adult  sponge  he  thinks  the 
descendants  of  the  latter  cells  which  line  part  of  the  canals  to  be 
alone  digestive,  the  collared  cells,  the  descendants  of  the  ciliated  cells, 
of  the  larva  being  mainly  respiratory. 

Sponge  -  spicules. — In  concluding  an  article  on  Plectronella  pa- 
pillosa,  a  new  genus  and  species  of  Echinonematous  sponge,§  Mr.  W. 
J.  Sollas  says  that  regarding  the  various  kinds  of  sponge-spicules  as 
resulting  from  a  variously  modified  cell-growth,  the  relations  sub- 
sisting between  the  chief  of  them  may  be  embodied  in  a  diagram. 

1.  An  elongate  growth  of  the  original  cell  in  two  opposite 
directions  at  equal  rates  gives  us  the  ordinary  acerate  spicule 
(Fig.  1),  which  is  biradiate  (diactinellid)  but  uniaxial. 

2.  A  retardation  of  growth  in  one  radius  gives  the  acuate  spicule 
of  Fig.  2. 

3.  A  linear  growth  in  one  direction  only  gives  the  acuate  (Fig.  3) ; 

*  N.  S.,  vol.  xix.  (1879)  p.  103. 

t  "  Untersuclmngen  iiber  d.  Bail  u.  d.  EutwiL-kelung  der  Spongien,"  'Ztitschr. 
f.  wiss.  Zool.,'  vol.  xxxi.  (1878). 
t  Ibid.,  vol.  xxiv.  (1874). 

§  •  Ann.  and  Mag.  Nat.  Hist.,'  ser.  5,  vol.  iii.  (1879)  p.  23. 
VOL.  II.  N 


178 


NOTES   AND   MEMORANDA. 


if  accompanied  by  increased  concentric  growth  of  the  initial  coll,  then 
the  pin-headed  acuate  (Fig.  4)  is  produced. 

4.  An  elongation  of  the  cell  in  two  directions,  inclined  to  each 
other  at  a  less  angle  than  180^,  gives  us  the  curved  acerate  (Fig.  5), 
which  is  both  biradiate  and  biaxial. 


fl         2      3        4 


As         11   6  7  8 


5.  The  inclination  of  the  two  rays  in  Fig.  5  is  followed  by  the 
appearance  of  a  third  in  Fig.  6,  where  we  have  the  triradiate  spicule 
of  Plectronella.  In  this  spicule  two  of  the  radii  arise  from  the  proximal 
face  of  the  cell  and  grow  inwards  towards  the  axis  of  the  fibre  on  which 
it  is  situated,  and  the  third  ray  arises  distally  and  grows  outwards 
away  from  the  axis. 

6.  A  growth  of  the  cell  in  three  directions  making  equal  angles 
with  each  other,  and  having  no  determinate  relations  to  any  sym- 
metrical line  within  the  sponge,  gives  us  the  equiangular  triradiate 
spicule  (Fig.  7),  which  occurs  abnormally  in  Dercitus  Bucldandi. 

7.  A  quadriradiate  growth  of  the  cell  in  directions  having  no 
determinate  relations  to  the  form  of  the  sponge  gives  us  the  normal 
spicule  of  Dercitus  Bucldandi  (Fig.  8). 

8.  The  cell  gives  oif  three  buds  from  its  distal  face,  which  grow 
outwards  away  from  the  sponge,  and  a  fourth  from  its  proximal  face, 
which  grows  inwards,  and  we  have  the  forked  forms  of  Geodia  and  the 
like  (Fig.  9). 

9.  The  cell  grows  in  five  directions  along  three  axes  at  right 
angles  to  each  other,  which  are  not  determinately  related  to  any  lines 
of  reference  within  the  sponge  [Dercitus  BucMandi),  or  which  are  so 
related  {Euplectella  and  other  Hexactinellids),  and  we  have  the  quinque- 
radiate  form  (Fig.  12). 

10.  In  Fig.  6  the  growth  of  the  three  rays  is  along  directions 
inclined  somewhere  about  120°  with  each  other ;  if  two  of  the  rays 
grow  in  opposite  directions,  and  the  third  at  right  angles  to  them, 


NOTES    AND    MEMORANDA.  179 

Fig.  10  results  (a  form  abnormal  in  Plectronella,  freq[uent  among  the 
Hexactinellidai). 

Fig.  11  requires  no  comment. 

Fig.  13  is  the  result  of  a  sexradiate  growth,  of  the  cell  along  three 
axes  at  right  angles  to  each  other,  and  represents  the  typical  Hexac- 
tinellid  spicule. 

Fig.  14  is  an  octoradiate  form,  seven  buds  having  grown  out 
radiately  in  one  plane  and  the  eighth  at  right  angles  to  them ;  it 
occurs  in  the  fossil  Hyalostelia. 

The  foregoing  remarks  arose  out  of  the  description  of  Plectronella 
papulosa,  which  was  the  main  object  of  the  paper ;  but  the  variability 
of  sponge-spicules,  Mr.  Sollas  points  out,  is  far  too  important  a  subject 
to  be  treated  thus  incidentally,  and  might  furnish  material  enough  for 
a  lengthy  memoir.  No  sj)onge  that  has  come  under  his  observation 
has  failed  to  exhibit  numbers  of  spicules  departing  more  or  less 
widely  from  the  average  type ;  frequently  the  range  of  variability  is 
extreme ;  and  no  doubt,  when  a  large  number  of  specimens  of  allied 
species  of  sponges  come  to  be  carefully  compared,  we  shall  find  not 
only  in  their  external  form,  but  in  the  details  of  their  internal  struc- 
ture as  well,  easy  j)assages  from  one  to  the  other,  and  links  will  be 
discovered  uniting  together  types  of  sponge-structure  that  now  appear 
widely  separated  from  one  another. 

Gloidium,  a  new  genus  of  Protista. — This  genus,  recently  dis- 
covered by  Dr.  N.  Sorokin,  of  Kasan,*  differs  in  many  respects  from 
any  of  the  hitherto  known  forms  of  Protista.  It  is  a  minute  myxopod 
( •  03  mm.  in  diameter),  with  short,  blunt  pseudopodia,  and  protoplasm 
distinctly  differentiated  into  a  clear  transparent  ectosarc,  and  a 
frothy-looking  endosarc  containing  reddish  or  j^ellowish  granules. 
There  is  no  nucleus,  but  a  large  contractile  vesicle  in  the  ectosarc, 
contracting  about  every  three  or  four  minutes. 

Multiplication  takes  place  by  division,  the  process  being  a  some- 
what singular  one.  Constrictions  appear  in  the  protoplasm  at  the 
opposite  poles,  and  soon  after  two  similar  constrictions,  the  plane  of 
the  second  division  being  at  right  angles  to  that  of  the  first.  Then 
the  pairs  of  constrictions  deepen,  extending  nearer  and  nearer  to  the 
centre,  until,  at  last,  four  masses  are  produced,  united  to  one  another  by 
as  many  delicate  threads  of  protoplasm  proceeding  from  a  common 
point  :  finally,  the  four  masses  become  free.  At  first  there  is  a  single 
contractile  vesicle  in  the  centre  of  the  dividing  mass,  but  as  division 
goes  on,  each  mass  is  provided  with  a  pulsating  organ. 

The  author  failed  to  see  any  food  particles  in  the  endosarc,  and 
supposes  that  the  organism  is  nourished  entirely  by  imbibition.  It 
is,  therefore,  devoid  of  one  of  the  most  constant  animal  characteristics 
— the  power  of  ingesting  solid  nutriment. 

Under  certain  circumstances  not  well  understood,  encystation 
takes  place.  A  thin,  scarcely  noticeable  investment  is  formed  by  the 
hardening  of  the  superficial  layer  of  ectosarc.  Fresh  layers  are  found 
in  the  same  way,  until  a  laminated  cyst  is  produced.     At  one  spot  all 

*  '  Morphologiscbes  JabrLuch,'  vol.  iv.  (1878). 


180  NOTES   AND   MEMORANDA. 

the  layers  but  the  outermost  one  are  undeveloped,  so  that  a  funnel- 
like canal  is  produced,  separated  from  the  exterior  only  by  the 
thin  outer  layer  of  the  cyst ;  into  this  canal — the  "  germinal  pore  " 
(Keimporus)  —  the  protoplasm  extends,  and  after  a  time  escapes 
through  it,  by  the  rujiture  of  its  thin  outer  covering.  The  process  of 
encystation  takes  one  and  a  half  to  two  hours ;  the  organism  remains 
encysted  from  two  to  three  days.  After  escaping  from  its  cyst,  it  is 
slightly  smaller  than  before.  No  union  of  different  individuals  into 
a  Plasmodium  was  observed,  so  that  the  life-history  of  Gloidium,  as  at 
present  made  out,  is  an  extremely  simple  one,  presenting  merely  an 
alternation  of  the  free  and  encysted  condition. 

Preparation  of  Microscopic  Aquatic  Animals. — An  anonymous 
writer  in  the  Berlin  '  Zeitschrift  fiir  Mikroskopie '  *  gives  an  account 
of  a  process  which  he  has  made  use  of  for  preparing  slides  of 
Infusoria,  Ehizopods,  Daphnia,  Cyclops,  Algte,  &c.  The  only  success- 
ful attempt  in  modern  times  to  supply  the  want  of  such  a  process  is 
that  of  Duncker,  of  Bernau,t  but  this,  for  trade  reasons,  is  kept  secret. 
The  author's  process,  which  he  thinks  may  be  identical  with 
Duncker's,  is  as  follows  : — 

By  means  of  a  pipette,  some  drops  of  the  liquid,  containing  the 
organisms  to  be  mounted,  are  introduced  into  a  lac  cell  not  quite  hard, 
and  covered  with  the  covering  glass.  Then  some  drops  of  rectified 
pyroligneous  acid  (acetum  pyrolignosum  rectificatum)  are  phaced  at  the 
edge  of  the  covering  glass  so  as  to  be  drawn  into  the  cell.  This 
liquid  immediately  kills  all  the  organisms  without  altering  their 
form.  It  only  remains  to  cement  the  cover  down  in  the  usual  way. 
When  the  pyroligneous  acid  has  become  turbid,  it  must  be  filtered 
before  being  used. 

With  this  method  may  be  combined  the  staining  of  the  objects  by 
anilin  colours.  Dissolve  one  jjart  (in  weight)  of  a  solution  of  anilin 
colour  (the  best  are  anilin  blue  or  diamond  fuchsin)  in  200  parts  of 
distilled  water ;  after  filtering,  add  800  parts  of  pyroligneous  acid. 
Then  with  this  liquid  proceed  as  with  the  pure  acid.  After  some 
hours,  the  objects  take  a  very  uniform  colour ;  they  are  then  mounted 
as  above,  after  adding  a  little  more  pure  acid.  If  the  colour  is  too 
dark,  it  can  be  made  lighter  with  acid.  The  author  thinks  that  his 
process  is  capable  of  improvement,  although  he  has  already  obtained 
excellent  results  from  it,  and  he  lays  stress  upon  the  facility  with 
which  it  can  be  used  in  travelling. 

The  Postal  Microscopical  Society. — This  Society  was  first 
established  in  1873,  as  the  "  Postal  Micro-Cabinet  Club,"  for  the 
purpose  of  affording  a  ready  means  of  communication  between  micro- 
scopists  living  not  only  at  a  distance  from  each  other,  but  also  from 
London  and  the  other  large  towns  having  Microscopical  Societies. 

The  Society  is  divided  into  circuits  of  twelve  members  each, 
whose  names  are  arranged  geographically.  A  box  of  slides  is  sent 
by  the  secretary  (Mr.  Alfred  Allen,  of  Bath),  at  fortnightly  intervals, 

*  '  Zeitschrift  fiir  Jlikroskopie,'  vol.  i.  (1878)  p.  273. 
t  This  Journal,  vol.  i.  p.  221. 


NOTES   AND   MEMORANDA.  181 

to  the  member  whose  name  stands  first  on  the  list,  who  should  keep  it 
three  evenings  only,  and  then  send  it  to  the  next  name,  and  he  to  the 
following  one,  the  last  on  the  list  returning  it  to  the  secretary,  by 
whom  it  is  sent  to  the  next  circuit,  and  so  on.  Each  box  is  accom- 
panied by  one  or  more  MS.  books,  in  which  the  members  are  requested 
to  make  remarks  on  the  slides. 

From  the  Fifth  Annual  Eeport  it  appears  that  the  Society 
numbers  140,  including  six  ladies  who  are  now  eligible  for 
membership.  In  the  Address  of  the  President,  Mr.  Tutfen  West, 
F.Z.S.,  F.R.M.S.,  the  safe  transit  of  slides  and  the  best  form  of  postal 
box  were  among  the  principal  topics  dealt  with. 

A  special  feature  is  the  requirement  of  the  Society  that  each 
member  on  admission  shall  send  his  carte  de  visite  to  the  secretary. 
They  are  then  grouped  (sixty  or  seventy  together)  and  reproduced  in 
permanent  photography  by  the  Woodbury  process,  and  supplied  to  the 
members. 

It  is  intended  to  circulate  a  separate  series  of  histological  and 
pathological  slides  amongst  the  medical  members. 

Life-History  of  the  Diatomacese. — M.  Paul  Petit,  whose  obser- 
vations on  the  revivification  of  diatoms  will  be  remembered,*  con- 
tributes to  the  French  Botanical  Society  some  further  remarks  f  on 
diatoms.  That  so  little  is  known  of  their  life-history  is,  he  thinks, 
the  fault  of  the  "  diatomophiles,"  who  have  preferred  to  create  new 
species  or  to  count  the  number  of  striae  on  the  valves  rather  than  to 
devote  themselves  to  physiological  researches.  The  impossibility  (as 
M.  Petit  considers)  of  growing  diatoms  in  an  aquarium,  as  can  be 
done  with  others  of  the  lower  cryptogamia,  necessitates  the  noting  of 
all  the  phenomena  which  are  met  with  in  nature.  We  shall  thus, 
sooner  or  later,  understand  the  ensemble  of  the  phases  through  which 
diatoms  pass  during  their  existence. 

He  accordingly  describes  the  following  observations  made  by 
Professor  Brun,  of  Geneva  : — 

On  the  5th-7th  of  January,  1878,  M.  Brun  gathered  some  mud 
which  covered  the  rocks  at  the  lower  part  of  the  Mer  de  Glace  at 
Chamounix  (1150  metres).  Deep  snow  covered  the  valley  and  the 
mountains,  the  thermometer  standing  at  18°  (C.)  below  zero  ;  but  as 
the  ice  melts  in  contact  with  the  rock  (even  in  winter),  the  rock 
is  thus  moistened  by  water  at  zero.  The  mud  contained  a  great 
quantity  of  diatoms  and  some  desmids,  all  in  a  perfect  state  of 
vegetation.  Lower  down  in  the  valley  a  small  piece  of  water  at  0^, 
covered  with  ice,  was  overrun  with  Melosira  varians  in  full  vegetation. 

Some  specimens  from  the  mud  of  the  Mer  de  Glace  were  sent  to 
M.  Petit  by  post,  and  he  found  that  the  endochrome  of  all  was  in  a 
perfect  state,  and  that  the  Naviciilce  exhibited  their  movement. 

The  second  observation  was  made  in  the  Valais,  on  the  Bella  Tola, 
at  2600  metres,  on  the  19th  and  20th  January.  The  temperature  was 
9°  below  zero,  and  the  snow  was  lying  thick.  Here  also  M.  Brun 
found  that  the  algae  and  diatoms  were  living  wherever  the  snow 
melted  in  contact  with  the  warmer  rock,  and  where  the  light  reached. 

*  This  Journal,  vol.  i.  p.  26.  f  '  BrtTbissonia,'  vol.  i.  (1878)  p.  81. 


182  NOTES   AND    MEMORANDA. 

The  specimens  sent  to  M.  Petit  contained  Melosira  arenaria  nearly 
pure,  containing  only  a  few  frustules  of  Surirelln  spiralis  and  Epithe- 
viia  helvetica.  It  was  easily  seen  at  the  first  examination  nnder  the 
Microscope  that  they  were  in  full  vital  activity. 

Thus,  according  to  these  ohservations,  diatoms  continue  to  live, 
and  even  to  develop,  in  water  at  0°  with  a  surrounding  temperature 
of  9°  to  18°  below  zero,  provided  always  that  they  receive  some  rays 
of  light. 

M.  Petit  further  says  that  "  it  is  extremely  curious  to  find  at  these 
great  altitudes  species  which  are  found  in  the  plains ;  it  is  impossible 
to  distinguish  any  difference  between  the  Alpine  species  and  the 
others." 

Movements  of  Diatoms  and  Oscillatorieae. — The  comparatively 
rapid  movements  in  the  water  of  diatoms  and  of  certain  desmids,  and 
the  wavy  motion  of  the  Oscillatorie^,  are  among  the  most  familiar 
phenomena  to  microscopic  observers ;  but  their  cause  is  at  present 
involved  in  much  obscurity. 

Professor  Engelmann,  of  Utrecht,  who  has  undertaken  extensive 
observations  on  the  subject,  thus  sums  up  our  present  knowledge.* 
The  most  probable  explanation  at  present  offered,  he  considers  to  be 
that  of  Max  Schultze,  f  who  attributes  them  to  the  movements  of  con- 
tractile protoplasm  which  covers  the  outer  surface  of  the  solid  cell- 
walls  ;  a  hypothesis  which  is  confirmed  by  the  following  considera- 
tions : — Diatoms  exhibit  this  power  of  motion  only  when  in  contact 
with  a  solid  siibstratum  ;  they  never  swim  freely  through  the  water ; 
which  contradicts  the  hypothesis  that  the  motion  is  due  to  vibratile 
cilia  or  to  osmotic  currents.  The  phenomenon  is  especially  marked 
when  they  lie  upon  one  of  their  so-called  "  sutures,"  and  the  motion 
is  always  in  the  direction  of  this  suture,  either  forwards  or  backwards. 
Foreign  bodies,  such  as  grains  of  indigo  or  other  pigments,  easily 
become  attached  to  the  surface  when  in  contact  with  a  suture,  and  are 
moved  up  and  down  along  it.  This  motion  of  the  foreign  particles 
takes  place  only  when  they  lie  upon  one  of  the  sutures,  and  then 
whether  the  diatom  itself  is  in  motion  or  at  rest. 

In  the  case  of  Oscillatorieae,  the  following  observations  have  been 
made  by  Siebold  :  J — If  the  water  in  which  these  bodies  grow  is 
coloured  by  indigo,  the  particles  of  this  pigment  which  come  into 
contact  with  the  separate  OsciUaria-^li\.ments  collect  into  a  rather 
narrow  sj)iral  running  round  the  filament  to  its  apex,  whether  the 
filament  is  in  motion  or  not.  Sometimes  these  creeping  spiral  lines 
of  jjigment  begin  to  be  formed  at  both  ends  of  the  filament,  and  meet 
in  the  middle,  where  the  particles  become  heaped  up  into  little  balls ; 
or  sometimes  they  begin  in  the  middle  and  advance  to  both  ends  of  the 
filament.  The  mode  in  which  the  particles  of  indigo  adhere  to  the 
alga  and  to  one  another  appears  in  this  case  also  to  indicate  an 
excretion  of  mucilaginous  protoplasm  by  the  former.     Cohn  §  subse- 

*  '  Botanische  Zeitung,'  vol.  xxxvii.  (1879)  p.  49. 

t  '  Archiv  fiir  Blikr.  Anat.,'  (1865)  pp.  376-402. 

X  '  Zcitsch.  fiir  wiss.  Zoologic,'  vol.  i.  (1849)  p.  284  ct  scq. 

§  Cohn,  in  '  Archiv  fiir  Mikroskopische  Anatomie,'  vol.  iii.  (1867)  p.  48. 


NOTES   AND    MEMOKANDA.  183 

quently  noted  the  same  peculiarity  with  regard  to  Oscillatoriese  that 
had  previously  been  observed  in  the  case  of  diatoms  : — that^  their 
oscillating  movements  take  place  only  when  they  are  in  contact  with 
a  solid  substratum. 

This  explanation  has  up  to  the  present  time  been  a  hypothetical 
one ;  but  the  extei'nal  secretion  of  protoplasm,  which  Schultze,  Siebold, 
and  Cohn  had  been  unable  to  discover,  has  at  length  been  detected  by 
Engelmann  in  the  case  of  a  large  oscillatoria,  Oscillaria  dubia,  Kiitz. 
The  method  by  which  he  at  length  succeeded  was  by  passing  induc- 
tion currents  through  the  water  in  which  the  alga  was  growing ;  when 
after  a  few  seconds,  an  excessively  thin  coating,  to  which  the  foreign 
particles  were  here  and  there  attached,  lifted  itself  from  the  surface 
of  the  alga,  but  never  to  a  greater  distance  than  about  0  *  008  mm. 
The  same  took  place  after  the  careful  addition  of  dilute  potash,  the 
protoplasm  subsequently  entirely  disappearing,  which  it  did  also 
gradually  on  addition  of  dilute  hydrochloric  acid  and  10  per  cent, 
solution  of  sodium  chloride.  With  eosin  and  picro-carmine  the  thin 
layer  became  distinctly  coloured.  The  protoplasmic  layer  was  also 
subsequently  made  visible  by  the  sudden  addition  of  strong  nitric 
acid.  It  is  probable  that  the  immobile  thread-like  cilia,  coloured 
yellow  by  iodine,  which  had  been  detected  in  some  Oscillatoriefe,  as 
Oscillaria  viridis  and  Phormidium  vidgare*  may  be  portions  of  the 
same  external  protoi^lasm. 

The  Use  and  Abuse  of  Diatoms  as  Test  Objects. — The  following 
remarks  are  not  strictly  new,  but  at  the  same  time  we  do  not  remember 
having  previously  seen  the  matter  so  well  put.  They  occur  in  a  paper 
by  Mr.  Gr.  D.  Hirst,  the  secretary  of  the  Section  of  Microscopical  Science 
of  the  Koyal  Society  of  New  South  Wales  ("  Notes  on  some  Local 
Species  of  Diatomacese "),  in  the  volume  recently  issued  of  that 
Society's  '  Journal  and  Proceedings  ' :  f — 

In  conclusion,  I  would  say  a  word  in  reply  to  questions  I  have 
heard  put  sometimes,  when,  after  the  expenditure  of  much  time, 
trouble,  and  patience,  adjusting  of  light  and  mirror,  the  lines  on 
some  difficult  test  diatom  have  at  last  been  fairly  displayed:  "Well, 
what  good  have  you  accomplished?  In  what  respect  is  microscopic 
science  benefited  by  the  fact  that  such  a  diatom  has  so  many  lines  to 
the  inch  ?  "  There  are,  I  know,  many  microscopists  who  affect  to 
despise  those  whom  they  call  "  Diatomaniacs,"  and  count  the  time  and 
trouble  expended  in  the  resolution  of  markings  as  simply  wasted. 
Now,  without  for  a  moment  arguing  that  the  only  or  chief  work  for 
the  Microscope  is  counting  the  strife  on  diatoms,  I  would  hold  that 
the  time  spent  in  successfully  resolving  a  difficult  test  is  by  no  means 
wasted.  The  tyro,  sitting  down  before  his  newly  acquired  instrument, 
places  an  object  on  the  stage,  turns  on  the  full  glare  of  light  from  his 
mirror  and  condenser,  and  fancies  he  sees  everything  to  perfection. 
Let  him  try  the  same  method  of  proceeding  on  some  delicate  diatom- 
valve  ;  and  where  in  the  hand  of  the  skilful  manipulator  a  moment 

*  Nageli,  in  '  Beitr'age  zur  wissenschaftliclien  Botanik,'  vol.  ii.  (1860)  p.  91. 
t  'Journal  and  Proceedings  of  the  Royal  Society  of  N.  S.  Wales,'  vol.  xi 
p.  272. 


184  NOTES   AND   MEMORANDA. 

before,  lines  or  beading  were  beautifully  displayed,  he  sees  a  blank. 
He  may  spend  long  hours  in  trying  every  trick  of  illumination,  mode- 
rating his  light,  varying  its  obliquity  by  altering  the  angle  of  his 
mirror,  focussing  and  re-focussing  the  condenser,  altering  the  adjust- 
ment of  his  objective  ;  and  at  last,  when  his  patience  is  well-nigh  ex- 
hausted, the  desired  result  is  obtained,  the  delicate  markings  start 
suddenly  into  view,  and  he  possesses  the  consciousness  that,  under  his 
hands,  mirror,  condenser,  and  objective  are  now  doing  their  best.  Has 
this  time  been  wasted  ?  I  think  not.  He  will  carry  the  knowledge 
obtained  in  the  struggle,  and  apply  it  in  the  broad  field  of  real  work 
that  lies  before  him  on  every  side.  Should  he  turn  his  attention  to 
the  development  of  minute  life,  organs  are  seen  in  living  transparent 
bodies  where  before  he  saw  nothing ;  should  he  be  a  pathologist, 
tissues  appear  full  of  structure  which  before  in  his  inexperienced 
hands  seemed  homogeneous,  minute  nerve-fibres  become  visible  where 
before  they  were  unsuspected.  I  do  not  think  I  am  exaggerating  in 
saying  what  I  have ;  I  have  felt  the  benefit  conveyed  in  an  education 
of  this  kind,  and  I  could  recommend  nothing  better  for  a  beginner 
than  a  year's  constant  study  of  all  the  species  of  Diatomacece  at  his 
command.  When  he  is  fully  convinced  that  he  sees  all  in  them  that 
his  optical  means  will  allow,  he  is  far  better  fitted  to  commence  real 
work  than  he  ever  could  have  been  without  this  preliminary  training. 
Only,  let  us  not  mistake  ;  our  work,  though  commencing  on  diatoms, 
should  not  end  there  ;  let  their  delicate  lines  be  the  means  of  familiar- 
izing ourselves  with  the  optical  capabilities  of  the  noble  instruments 
at  our  disposal,  and  the  questions  I  have  quoted  will  be  duly  answered 
— the  time  spent  will  not  be  in  vain. 

To  the  same  effect  are  some  remarks  made  by  Mr.  J.  Mayall, 
jun.,  in  an  address  on  "  Immersion  Illuminators,"  recently  delivered 
before  the  Brighton  and  Sussex  Natural  History  Society : — "  Practice 
with  diatoms  should  be  regarded  as  the  gymnastics  of  the  Microscope. 
To  ignore  this  practice  is  voluntarily  to  paralyze  our  possible  skill, 
which  cannot  be  done  with  impunity,  as  is  proved  by  the  immense 
mass  of  old  results  that  are  constantly  being  discarded  to  make  way 
for  interpretations  based  on  more  perfect  instrumental  and  manipula- 
tive means.  The  improvements  in  the  Microscope  are  almost  wholly 
due  to  the  criticisms  of  amateurs  skilled  in  the  exhibition  of  test 
objects." 

Measurement  of  the  Amplification  of  Optical  Instruments.— 
The  following  was  communicated  by  M.  Govi  to  the  French  Academy, 
and,  being  printed  in  their  '  Proceedings,'*  we  have  thought  that  a 
translation  might  properly  find  a  place  here.  Those  who  may  not 
altogether  agree  with  the  views  expressed,  may  still  find  some  interest 
in  the  fact  of  the  paper  having  been  accepted  by  the  Academy : — 

By  amplification  is  meant  the  relationship  of  size  between  the 
image  and  the  object.  The  idea  of  size,  obtained  by  looking  at  an 
image,  without  actually  measuring  it,  is  not  in  any  way  precise. 

If  optical  instruments  only  gave  real  images,  their  magnifying 

*  '  Comptcs  Rcudus,'  vol.  Ixxxvii.  (1878)  p.  726. 


NOTES   AND    MEMOBANDA.  185 

power  would  be  very  easily  determined,  and  there  could  be  no  dispute 
as  to  it.  Virtual  images  bave,  nevertheless,  quite  as  measurable  a 
size  as  real  images,  and  have,  like  the  latter,  a  determinate  place  in 
space. 

We  must  not,  then,  gratuitously  suppose  that  the  eye  constantly 
refers  them  to  the  distance  of  distinct  vision,  because,  first  of  all,  such  a 
distance  does  not  exist  for  normal  eyes,  and  that,  if  even  it  did  exist, 
it  would  not  be  of  any  use  for  the  measurement  of  the  amplification ; 
since  each  observer,  and  the  same  observer  every  time  that  he  re- 
focusses  an  image,  places  it,  or  may  place  it,  at  a  different  distance. 

It  is  sufiicient,  to  jjrove  tbis,  to  make  several  people  focus  an 
image,  and  examine  its  distance  every  time,  by  means  of  a  megameter* 
a  little  astronomical  telescope  with  graduated  draw-tube  and  micro- 
meter eye-piece.  It  is  thus  found  that  nearly  all  the  focussings  give 
different  distances. 

The  megameter  enables  us,  besides,  to  measure,  in  every  case,  the 
actual  size  of  the  image,  by  referring  it,  by  the  micrometer  eye-piece, 
to  a  divided  scale,  looked  at  directly  through  the  megameter,  of  which 
the  focus  has  not  been  changed.  The  image  once  measured,  it  only 
remains  to  divide  it  by  the  size  of  the  object  in  order  to  have  the 
amplification. 

The  camera  lucida  and  the  process  of  double  vision  ("  double  vue  ") 
also  give  the  means  of  measuring  the  amplification,  because  the  eye  is 
a  pretty  good  judge  of  the  distance  of  images,  and  consequently  of 
their  size,  when  it  can  compare  them  to  different  objects  whose  place 
is  exactly  determined  (pencil,  paper,  divided  scale,  &c.).  In  having 
recourse  to  these  processes  of  measurjment,  we  recognize  that  in- 
struments with  virtual  images  give  all  the  amplifications  possible,  from 
a  minimum  up  to  infinity,  each  corresponding  to  a  different  distance 
of  the  image. 

It  is  therefore  inexact  to  say  that  such  and  such  a  lens,  or  Micro- 
scope, magnifies  the  image  of  objects  a  certain  number  of  times,  unless 
we  add  at  what  distance  such  an  image  ought  to  be  for  the  indicated 
amplification  to  be  realized. 

The  magnifying  power  of  different  instruments  could  be  exactly 
defined,  by  measuring  for  each  of  them  the  amplification  produced  at 
a  fixed  distance — a  decimetre,  for  example — because  all  other  amplifi- 
cations could  be  deduced  from  that,  with  sufficient  exactitude,  by  a 
simple  proportion. 

What  has  led  to  the  supposition  that  virtual  images  (in  the  Micro- 
scope especially)  were  constantly  referred  to  the  same  distance  (the 
distance  of  distinct  vision),  is  probably  the  fact  that,  in  spite  of  the 
enormous  variation  of  distance  and  size,  which  vii'tual  images,  given 
by  optical  instruments,  undergo,  they  always  subtend  in  the  eye  nearly 
the  same  augle,|  do  not  vary  sensibly  in  brilliancy,  neither  lose  nor 

*  See,  on  the  measurement  of  map;nifying  powers  and  the  use  of  tlie  mega- 
meter, 'Monitore  toscano,'  20  August,  1861 ;  'Memorie  dtUa  R.  Accademia  delle 
Scienze  di  Torino,'  vol.  xxiii.  pp.  455-4(35;  'Nuovo  Cimento,'  vol.  xvii.  p.  177. 

t  The  method  employed  by  astronomers  to  measure  the  amjilification,  gives 
accurate  results,  in  consequence  of  the  almost  absolute  invariability  of  the  angle 
subtended  by  the  image. 


186  NOTES   AND    MEMORANDA. 

gain  in  any  of  their  details,  and  seem  consequently  not  to  move  in 
space.  In  Microscopes  of  liigh  magnifying  power,  the  tenuity  of  the 
pencils  of  rays  which  start  from  every  point  of  the  imago  also  contributes 
to  make  its  position  in  space  uncertain  to  the  eye,  since  the  accommoda- 
tion is  no  longer  necessary  in  order  to  see  it  tolerably  clearly.  How- 
ever, it  none  the  less  exists  in  a  definite  place  in  space,  where  we  must 
go  to  measure  it  in  order  to  know  the  true  amplification ;  and  here 
again  the  megameter  can  be  employed  with  advantage. 

Discosporangium,  a  new  genus  of  Phaeosporese.— The  fact  that 
the  majority  of  Phfeosporea3  are  only  to  be  met  with  during  a  portion 
of  the  year,  led  M.  Falkenberg  (at  the  Naples  Zoological  Station)  * 
to  the  conjecture  tliat  they  may  at  certain  periods  withdraw  themselves 
to  great  sea-depths.  Although  this  conjecture  was  not  confirmed,  it 
led  to  the  discovery  of  a  new  genus  at  a  depth  of  15  metres,  off  Cape 
Misenum.  This  sea-weed,  to  which  Falkenberg  gives  the  name 
Discosporangium  svhtile,  consists  of  filaments  of  cells  growing  by  an 
ai)ical  cell.  They  have  lateral  branches,  springing  from  the  middle 
of  the  cells  of  the  filament.  The  origin  of  the  sporangia  (zoo- 
sporangia)  is  the  same.  They  are  placed  solitary  at  the  centre  of  the 
cells,  and  form  a  unilamellar  square  plate,  the  compartments  of  which 
open,  when  ripe,  on  the  upper  side  of  the  sporangium.  The  furtlier 
development  of  the  zoospores  was  not  observed.  The  author  suggests 
that  the  zoospores  produced  in  unilocular  and  plurilocular  sporangia 
of  the  PhfeosporesB  perform  different  functions.  Although  the  sys- 
tematic position  of  Discosporangium  is  still  doubtful,  Falkenberg 
considers  its  nearest  ally  to  be  Choristocarpus,  a  genus  separated 
from  the  Ectocarpese  by  the  mode  of  development  of  the  thallus.  In 
the  course  of  his  researches  the  author  had  the  opportunity  of  con- 
firming the  observations  of  Sirodot  on  the  genetic  connection  of 
Chantransia  and  Batracliospermum.  He  also  gives  a  list  of  a  con- 
siderable number  of  species  of  marine  Floridete  which  bear  on  the 
same  individual  both  tetraspores  and  capsular  fruits,  as,  for  instance, 
species  of  Callitliamniun  and  Polysiplionia. 

Reproduction  of  Ulvacese. — The  reproduction  of  three  species, 
Monostroma  hullosum,  Tetraspora  lubrica,  and  Ulva  rigida  has  been 
studied  by  J.  lieinke.l  In  the  first-named  species  he  observed  the 
formation  and  conjugation  of  the  zoospores,  the  development  of  the 
resulting  zygospore  into  a  resting  sj)ore,  and  the  subsequent  con- 
version of  the  latter,  by  division  of  its  contents,  into  a  young 
31onostroma  thallus.  The  non-sexual  reproduction  of  the  plant  was 
also  observed. 

The  observations  on  Ulva  rigida  showed  that  in  this  species  also 
new  individuals  are  produced  from  resting  spores  without  the  inter- 
mediate formation  of  zoospores. 

In  Tetraspora  luhrica  the  macrozoospores,  after  a  short  free  ex- 
istence, settle  down  and  divide  into  four-,  the  daughter-cells  being 
either  all  in  one  plane,  or  arranged  tetrahedrally.     Multiplication 

*  '  Mittheihmgcn  der  Zoologischen  Station  zu  Neapcl,'  vol.  i.  (1878)  p.  51. 
t  '  Jalirb.  f.  wis3.  Bot.,'  vol.  xi.  (1878)  p.  531. 


NOTES   AND    MEMOEANDA.  187 

of  these  cells  begins  and  continues,  in  the  first  case,  in  one  plane,  in 
the  second  radially.  Usually  several  macrospores  come  to  rest 
together,  and  then  the  young  tballi  formed  from  them  fuse  together 
into  a  single  irregular  mass.  The  formation  of  microzoospores  was  also 
observed,  and  their  conjugation ;  the  resulting  zygospore  grew  to  the 
size  of  a  macrospore,  and  then  divided  in  the  same  way  as  the  latter. 

Nostoc-colonies  in  Anthocerotese. — The  colonies  of  parasitic  Nostoc 
occurring  in  the  thallus  of  various  species  of  Anthoceroteoe  were  in- 
vestigated some  years  siuce  by  Janczewski,  and  have  now  been  studied 
again  by  Leitgeb.  *  He  finds  that  the  motile  filaments  of  the 
parasites  penetrate  through  the  young  stomata,  the  air-cavities  in  con- 
nection with  them  being  then  filled  with  mucilage.  Sometimes,  how- 
ever, infection  seems  to  be  brought  about  by  a  few  isolated  Nostoc-ceWs, 
or  even  by  a  single  cell.  It  is  j^robable  that  there  is  more  than  one 
species  of  Nostoc  inhabiting  the  different  genera  of  Anthocerotete,  but 
this  is  not  certain. 

For  further  details  we  must  refer  our  readers  to  the  paper  itself. 
It  is  illustrated  by  one  plate,  showing  the  formation  of  the  stomata 
and  air-cavities,  and  the  relation  of  the  ^os/oc-colonies  to  them. 

Support  for  the  Head  in  Drawing  with  the  Camera  Lucida. — A 

writer  in  '  Science-Gossip' t  points  out  the  assistance  which  the 
draughtsman  will  receive  by  keeping  the  head  steady  as  well  as  the 
hand,  and  explains  a  device  he  has  made  use  of  for  tlais  pixrpose.  It 
consists  simply  of  two  upright  brass  rods  with  a  flat  sliding  cross- 
bar (covered  with  some  soft  subst  mce)  between  them,  which  can  be 
screwed  tight  at  any  height,  and  on  which  the  forehead  is  placed  in 
the  position  desired. 

Alcoholic  Fermentation. — The  '  Comptes  Eendus '  have  continued 
to  contain  further  "  observations "  and  "  replies "  on  the  discussion 
raised  between  M.  Pasteur  and  M.  Berthelot  in  regard  to  the  i>osthu- 
mous  MSS.  of  the  late  Claude  Bernard.  We  noticed  at  p.  270  of 
vol.  i.  the  commencement  of  the  controversy,  and  at  p.  82  of  this 
volume  M.  Pasteur's  refutation  of  M.  Bernard's  views.  This  was 
criticised  by  M.  Berthelot,  J  who  maintained  his  original  view,  that 
the  action  of  ferments  is  reducible  to  purely  chemical  conditions 
independent  of  life ;  to  whom  M.  Pasteur  again  replied,  §  charging 
M.  Berthelot  with  putting  forward  entirely  gratuitous  hypotheses 
which  have  never  been  supported  by  any  personal  observations.  He 
thus  describes  the  hypotheses : — 1st.  In  alcoholic  fermentation  there 
is  perhaps  produced  a  soluble  alcoholic  ferment.  2nd.  This  soluble 
ferment  perhaps  consumes  itself  in  proportion  to  its  production. 
3rd.  There  are  perhaps  conditions  in  which  this  hypothetical  ferment 
would  be  produced  in  greater  proportion  than  the  amount  destroyed. 
M.  Pasteur  deals  seriatim  with  M.  Berthelot's  objections,  and  says 
that  if  he  will  endeavour  to  support  his  hypotheses  by  experiments, 

*  'Sitzungsb.  k.  Wiener  Akad.  dii  Wiss.,'  vol.  Ixxvii.  (187S)  p.  411. 
t  'Hardwicke's  Science-Gossip,'  No.  170  (1879)  p.  32. 
X  '  Comptes  Rcndus,'  vol.  Ixxxvii.  (1878)  p.  949. 
§  Ibid.,  p.  1053. 


188  NOTES   AND    MEMOKANDA. 

and  should  discover  a  soluble  alcoholic  ferment,  he  (M.  Pasteur) 
would  applaud  his  discovery,  which  would  be  very  interesting,  and 
not  in  any  way  annoying.  If  he  should  arrive  at  conclusions  contrary 
to  the  principles  established  by  M.  Pasteur,  the  latter  assures  him 
that  "  he  would  hasten  to  do  for  those  conclusions  what  he  has  done 
for  Bernard's,  viz.  demonstrate  their  fallacies,"  and  he  calls  upon 
M.  Berthelot  to  controvert  his  statements,  not  by  a  priori  theories,  but 
by  serious  facts. 

On  this  reply  M.  Trecul  made  some  observations*  tending  to 
charge  M.  Pasteur  with  holding  contradictory  opinions  in  stating 
that  he  adhered  to  his  original  classification  of  microbia  into  aerobic 
or  azymic,  and  anaerobic  or  zymic,  while  at  the  same  time  founding  a 
third  class,  which,  according  to  circumstances,  have  the  property  of 
living  in  air  or  without  oxygen.  M.  Pasteur  contented  himself  with 
saying  that  M.  Trecul's  memory  was  at  fault,  and  that  since  1861  he 
has  always  maintained  the  existence  of  the  three  kinds  of  organisms. 

Another  "Reply  to  M.  Pasteur"  from  M.  Berthelot  was  read  on 
the  6th  January,!  in  which,  after  some  preliminary  remarks,  he 
"  comes  to  the  question  of  the  organisms  which  borrow  from  the  sugar, 
according  to  M.  Pasteur,  combined  oxygen  in  place  of  the  free 
oxygen  with  which  the  air  provides  them  in  the  ordinary  conditions 
of  their  existence."  He  retorts  upon  M.  Pasteur  the  absence  of  any 
support  from  "  serious  facts,"  and  asserts  that,  on  the  contrary, 
serious,  positive  facts  prove  that  the  "  nutrition  of  yeast  results  from 
a  complex  ensemble  of  chemical  transformations,  an  ensemble  which 
it  would  be  dangerous  to  the  progress  of  science  to  simplify  by  the 
apparent  clearness  of  a  pure  supposition  founded  on  a  physiological 
antithesis.  A  sufficient  number  of  valuable  discoveries  have  esta- 
blished the  reputation  of  M.  Pasteur,  so  that  he  can  give  up  without 
detriment  a  theory  so  little  justified  by  facts." 

M.  Trecul  subsequently  laid  before  the  Academy  |  a  detailed 
paper,  in  which  he  endeavoured  to  establish  his  assertions  by  nume- 
rous extracts  from  M.  Pasteur's  writings.     M.  Trecul  considers : — 

1st.  That  the  organized  ferments  are  only  particular  states  of 
more  or  less  complicated  species,  which  are  modified  according  to  the 
media  in  which  they  are. 

2nd.  That  in  place  of  establishing  three  classes  of  inferior  organ- 
isms, as  M.  Pasteur  proposes,  there  is  really  only  one,  each  species 
being  able  to  present  one  or  many  aerobian  states,  and  one  or  many 
anaerobian  states. 

The  activity  of  the  subsequent  controversy  may  be  judged  of  by 
a  reference  to  our  "  Bibliography,"  where  will  be  found  the  list  of  the 
"Eeplies,"  "Second  Replies,"  "Third  Replies,"  "Fourth  Replies," 
"  Last  Eeplies,"  and  further  "  Observations,"  and  "  Notes  "  of  MM. 
Pasteur,  Berthelot,  and  Trecul,  with  which  the  subsequent  numbers 
of  the  '  Comptes  Rendus  '  abound. 

The  discussion  between  M.  Pasteur  and  M.  Trecul  was  closed  by 

*  '  Comptes  Eendus,'  vol.  Ixxxvii.  p.  1058. 
t  Ibid.,  vol.  Ixxxviii.  (1879)  p.  18. 
t  Ibid.,  p.  54. 


NOTES   AND   MEMORANDA.  189 

the  following  "  reply  "  of  the  former :  * — "  Ma  classification  est  ce 
qu'elle  est.  Acceptez-la  ou  rejetez-la,  cela  vous  regarde.  Pour  moi 
elle  est  excellente  !  " 

Bacteria  in  the  Poison  of  Serpents. — M.  Lacerda  calls  the  atten- 
tion of  the  French  Academy  to  a  fact  he  observed  at  the  physiological 
laboratory  at  Rio  de  Janeiro. 

Contrary  to  the  general  belief  that  the  venomous  matter  is 
nothing  but  a  poisonous  saliva  acting  like  soluble  ferments,  he  observed 
facts  which  prove,  in  his  opinion,  that  it  contains  figured  ferments, 
whose  analogy  with  bacteria  was  remarkable.  Subjecting  a  snake  to 
chloroform,  he  extracted  from  it  a  drop  of  its  poison  on  a  glass 
plate,  previously  washed  in  alcohol  and  slightly  warmed.  Imme- 
diately placing  it  under  the  Microscope,  a  kind  of  protoplasmic 
filamentous  matter  was  seen,  formed  of  an  aggregation  of  cells, 
arranged  in  an  arborescent  form  like  certain  Lycopodiacese. 

Gradually  the  filament  (enlarged  where  the  spores  are)  is  dis- 
solved and  disappears,  and  the  spores  are  set  at  liberty,  assuming  a 
linear  arrangement.  Then,  if  the  conditions  of  the  surrounding 
medium  are  favourable  to  their  development,  they  swell  and  enlarge 
sensibly,  pushing  out,  after  a  time,  a  kind  of  small  tube,  which  quickly 
lengthens.  This  soon  sej^arates,  and  forms  another  sj)ore,  which  is 
reproduced  in  the  same  way. 

When  these  si^ores  have  attained  a  certain  size,  a  filament  is 
observed  in  their  interior,  which  becomes  more  and  more  marked, 
and  presents  here  and  there  ovoid  and  very  refractive  corpuscles ;  in 
a  short  time  the  protoplasm  of  the  spore  is  retracted,  its  membrane 
is  dissolved,  and  the  corpuscles  are  set  at  liberty  to  continue  after- 
wards the  same  process  of  reproduction. 

The  spores  have,  however,  two  principal  modes  of  multiplication — 
by  scission  and  by  internal  nuclei.  In  the  blood  of  animals  killed  by 
the  bite,  the  following  phenomena  were  observed  : — 

The  red  globules  began  by  showing  small  brilliant  points  on 
the  surface  of  the  disk,  which  sometimes  formed  projections  and 
became  more  and  more  numerous.  By  following  attentively  the 
different  phases  of  the  change,  he  succeeded  in  seeing  the  globule 
completely  destroyed,  and  replaced  by  numerous  ovoid  very  brilliant 
corpuscles,  endowed  with  spontaneous  oscillatory  movement.  Some- 
times they  were  not  disengaged  from  the  globular  mass,  but  remained 
enclosed  within  it,  and  the  globules  became  fused  with  each  other, 
forming  a  sort  of  amorphous  very  diffluent  paste. 

The  animals  in  which  a  hypodermic  injection  was  made  of  the 
blood,  immediately  after  the  death  of  the  animal  bitten,  all  died  in  a 
few  hours,  with  almost  the  same  symptoms,  and  their  blood  always 
showed  the  same  changes  remarked  in  animals  directly  poisoned. 

M.  Lacerda  also  ascertained  that  alcohol  injected  under  the  skin, 
or  introduced  through  the  mouth,  is  the  real  antidote  against  this 
ferment. 

In  presenting  this  paper,  M.  de  Quatrefages  added  that  in  his 

*  '  Comptes  Eendus,'  vol.  Ixxxvii.  p.  255. 


190  NOTES   AND   MEMORANDA. 

opinion  it  was  necessary  to  make  "serious  reserves  as  to  tlie  conclu- 
sions of  the  author." 

Flagellated  Organisms  in  Rats'  Blood. — In  the  'Fourteenth 
Annual  Report  of  the  Sanitary  Commissioner  with  the  Government 
of  India  '  is  a  paper  on  "  the  Microscojiic  Organisms  found  in  the 
Blood  of  Man  and  Animals,"  by  Mr.  T.  E.  Lewis,  M.B.,  in  which 
he  disputes  the  correctness  of  what  he  terms  one  of  the  fundamental 
tenets  of  M.  Pasteur's  creed,  viz.  that  neither  microscopic  organisms 
nor  their  germs  are  ever  found  in  the  blood  of  an  animal  in 
health. 

In  July,  1877,  he  detected  organisms  in  the  blood  of  a  rat  which 
he  was  examining.  Under  the  Microscope,  the  blood  appeared  to 
quiver  with  life,  and  on  diluting  it  with  a  half  per  cent,  solution  of 
salt,  motile  filaments  could  be  seen  rushing  through  the  serum,  and 
tossing  the  blood-corpuscles  about  in  all  directions.  Their  move- 
ments were  of  a  more  undulatory  character  than  spirilla,  and  the  fila- 
ments were  thicker,  more  of  a  vibrionic  aspect.  They  were  pale 
translucent  beings,  without  any  trace  of  visible  structure  or  granu- 
larity. It  was  observed  that  every  now  and  then  blood-corpuscles 
some  considerable  distance  from  any  visible  motile  filament  would 
suddenly  quiver.  On  carefully  arranging  the  light,  it  was  seen  that 
this  was  due  to  a  very  long  and  exceedingly  fine  (apparently  posterior) 
flagellum.  These  haematozoa  may  sometimes  be  kept  alive  for  two  or 
three  days,  but  generally  die  and  disappear  from  view  within  twelve 
or  twenty-four  liours,  as  though  they  had  been  dissolved  in  the  serum 
in  which  they  were  found.  They  may  be  preserved  by  spreading  out 
a  thin  layer  of  the  blood  containing  them  over  a  thin  covering  glass, 
and  inverting  it  over  a  weak  solution  of  osmic  acid.  The  preparation 
should  be  removed  as  soon  as  it  presents  a  dry,  glazed  appearance, 
and  may  be  thus  mounted  in  the  dried  condition,  or  in  a  saturated 
solution  of  acetate  of  potash.  The  flagellrmi  cannot  be  detected  in 
such  a  preparation ;  apparently  the  refractive  index  of  the  substance 
forming  the  flagellum  and  that  of  the  serum  approximates  so  closely, 
that  it  can  only  be  detected  when  creating  a  current  by  its  movements. 

The  body-portion  may  be  measured  after  they  have  been  killed  by 
means  of  osmic  acid.  The  width  of  the  anterior  half  or  body-portion 
averages  •  8  to  1  /x,  or  precisely  that  of  ordinary  blood-bacilli,  and  its 
length  from  20  to  30  fx.  The  flagellum,  so  much  of  it  as  is  visible, 
is  somewhat  of  the  same  length,  though  possibly  considerably  longer, 
as  the  slope  from  the  body-portion  is  very  gradual ;  and  when  the  eye 
follows  it  to  the  bounds  of  visibility,  an  impression  is  conveyed  that 
there  may  be  still  more  of  it. 

On  applying  electricity  to  a  drop  of  the  blood,  it  was  found  that 
an  interrupted  current  of  such  a  strength  as  could  not  be  comfortably 
borne  by  an  individual  was  tolerated  by  these  beings  for  several  con- 
secutive hours. 

The  species  of  rats  in  which  these  organisms  were  found  were 
BIus  decumanus  and  31.  riifescens.     They  were  never  found  in  mice.* 

*  'Quart.  Journ.  Mic.  Sci.,'  N.  P.,  vol.  xix.  (1879)  p.  109. 


NOTES   AND   MEMORANDA.  191 

Deceptive  Appearances  produced  by  Reagents. — A  paper  recently 
communicated  by  Dr.  George  Tbiu  to  the  Royal  Society  *  under  this 
title,  was  intended,  in  addition  to  being  a  contribution  to  the  histology 
of  hyaline  cartilage,  to  illustrate  how  much  the  apj^arent  structure 
of  a  tissue  which  is  being  examined  microscopically  depends  on 
methods  of  preparation. 

In  the  examination  of  a  cartilaginous  tumour  of  the  lower  jaw, 
the  author  was  able  to  isolate  the  cells  from  the  cartilaginous  sub- 
stance of  the  tumour  after  the  action  of  osmic  acid.  All  the  cells 
observed  were  flattened,  rounded,  or  somewhat  polygonal  bodies,  with 
round  nuclei.  Their  contours  did  not  correspond  exactly  with  those 
of  the  rounded  cartilage  "  capsules  "  in  which  they  lay. 

The  examination  of  this  tumour  showed  that  most  delusive  appear- 
ances as  regards  the  nature  of  cartilage  cells  may  be  sometimes  pro- 
duced by  staining  and  hardening  agents.  Carmine  and  eosin,  by 
staining  an  unformed  substance  that  exists  in  the  structure  in  defined 
tracts,  may  simulate  branched  protoplasmic  cells,  and  bichromate  and 
logwood  preparations,  either  in  sections  or  teased  out,  may  as  closely 
simulate  cells  with  fibre  processes. 

These  facts  justify,  the  author  considers,  serious  doubts  as  to  the 
correctness  of  interpretation  in  all  cases  in  which  histologists  have 
described  branched  cells  in  hyaline  cartilage,  whether  the  latter 
existed  as  a  normal  structure  or  as  a  pathological  growth.  They 
further  show  that,  taken  alone,  carmine  or  eosin-staining  should  not 
be  held  as  conclusive  evidence  of  the  existence  or  limits  of  cellular 
protoplasm  in  any  animal  tissue. 

Preparation  of  Red  Blood-corpuscles.— Very  excellent  perma- 
nent preparations  of  the  red  blood-corpuscles  of  Amphibia  may  be 
made  by  Eanvier's  method,  as  follows :— Some  blood  is  allowed  to 
drop  from  a  wound  into  about  two  hundred  times  its  volume  of  a  satu- 
rated picric  acid  solution.  After  a  few  minutes  the  picric  acid  is 
carefully  poured  off,  leaving  most  of  the  corpuscles  at  the  bottom  of 
the  dish ;  a  solution  of  picro-carmine  is  then  poured  over  them,  and 
allowed  to  stand  a  day  or  two.  The  picro-carmine  is  then  poured  off, 
and  the  sediment  put  into  acid  glycerin  (glycerin  100  parts,  acetic 
acid  1  part).  The  corpuscles  so  treated  will  last  a  long  time,  and 
may  be  mounted  in  the  acid  glycerin  at  any  time.  The  nuclei  of 
the  corpuscles  are  stained  bright  red,  and  the  body  light  yellow. 
Corpuscles  of  Menohranchus,  which  are  about  twice  as  large  as  those 
of  the  frog,  prepared  in  this  way  nearly  a  year  ago,  appear  perfect  as 
ever. 

Apparatus  for  Determining  the  Angle  of  the  Optic  Axes  of 
Crystals  with  the  Microscope.— Professor  A.  de  Lasaulx,  referring 
to  a  previous  paper,J  in  which  he  described  a  method  he  had  devised 
for  this  object,  says  that  it  often  presents  difficulties,  as  it  supposes 

*  'Proc.  Roy.  Soc.,'  vol.  xxviii.  (1878)  p.  257. 

t  Mr.  S.  H.  Gag.',  in  'Amcr.  Quart.  Mic.  Joiirn.,'  vol.  i.  (1879)  p.  160. 
X  'Bulletin  de  la  Socie'te  Beige  de  Micro.scopie,'  vol.  iv.  (1878)  p.  177,  noticed 
in  part  in  this  Journal,  vol.  i.  p.  207 


192 


NOTES   AND   MEMORANDA. 


that  we  have  two  thin  plates  of  the  mineral  to  be  examined,  cut 
perpendicularly  to  one  another.  In  the  case  of  all  minerals  whose 
cleavage  in  one  direction  is  very  perfect,  it  is  difficult,  and  often  even 
impossible,  to  cut  a  thin  plate  normal  to  the  direction  of  the  cleavage. 
It  was,  therefore,  desirable  to  be  able  to  determine  the  apparent  angle 
of  the  optic  axes  by  direct  measurement  with  the  Microscope.  In  all 
cases  where  a  mineral  only  becomes  transparent  when  the  plates  are 
very  thin,  the  determination  of  the  angle  of  the  optic  axes  can  only  be 
eifected  in  general  with  the  Microscope. 

To  arrive  at  this  result,  the  distance  of  the  poles  of  the  optic  axes 
of  a  mineral,  as  seen  in  the  interference  image,  must  be  compared  with 
this  same  distance  in  a  film  of  biaxial  mica,  for  which  the  angle  of  the 
optic  axes  has  been  determined  by  an  instrument  specially  designed  to 
measure  it. 

To  make  a  sufficiently  exact  comparison  of  the  distances  of  the 
poles  in  the  film  of  mica,  and  in  the  thin  plate  of  the  mineral  to 
be  examined,  we  must  be  able  to  measure  exactly  these  two  distances 
in  the  Microscope.  As  the  eye-piece  is  removed  in  order  to  see  the 
interference  image,  the  eye-piece  micrometer  cannot  be  used  without 
employing  lenses  by  which  the  interference  image  is  distorted. 

The  following  form  of  apparatus  has  accordingly  been  designed  by 
Professor  de  Lasaulx.  On  the  edge  of  the  setting  of  the  upper  Nicol, 
a  brass  cover  A  (Fig.  1)  is  fixed  by  screws  d,  having  a  diaphragm  of 


Mj./ 


h   B 


the  same  size  as  the  glass  which  covers  the  Nicol.  At  one  side  there 
is  a  horizontal  axis  which  can  be  turned  by  the  screw  a,  and  at  the 
same  time  this  axis  and  the  plate  which  it  supports  can  be  turned  round  a 
screw  h.  This  axis  holds  an  ordinary  covering  glass  c,  through  which 
may  be  seen  the  image  in  the  Microscope.  A  rod  C  carries  the  other 
part  of  the  apparatus  B,  which  consists  of  a  blackened  rectangular 
screen  with  a  very  fine  horizontal  slit  h  ( Fig.  2)  in  the  middle.  On 
one  side  the  screen  has  a  small  slide  /,  which  by  the  screw  e  passing 
through  I,  may  be  moved  in  the  grooves  h  to  the  right  or  to  the  left, 


NOTES    AND    MEMORANDA. 


193 


and  the  slit  opened  or  sliut.     One   of  tbe  grooves  Las  a  graduated 
scale,  by  which  the  length  of  the  oi^en  slit  is  shown. 

The  apparatus  is  fixed  on  the  Microscope  in  such  a  way  that  the  slit 
in  the  screen  is  illuminated  by  the  light  of  the  window.     If  the  glass  c 


Ma^ 


TTtrmWt 


Dtw 


is  then  raised  to  an  angle  of  45°  with  the  horizon,  no  difficulty  will  be 
experienced  in  seeing  a  reflected  image  of  the  slit  li  on  the  glass,  in 
the  middle  of  the  diaphragm  of  A.  Hence,  looking  through  the  glass 
into  the  Microscope,  we  see  simultaneously  the  interference  image  and 
the  reflected  image  of  the  slit,  which  appears  as  a  brilliant  line.  It 
now  remains  to  bring  one  of  the  two  extremities  of  the  image  of  th^ 
slit  over  one  of  the  visible  poles  of  the  optic  axes.  That  this  may  be 
done,  the  screen  B  is  movable  on  the  plate  m,  which  serves  as  its 
base,  and  with  which  it  is  fixed  by  the  screw  /  on  the  rod  C  ;  the  two 
screws  </  are  inserted  in  the  oblong  openings  /,  and  by  loosening  these 
screws  a  little  the  screen  can  be  moved  upon  the  base-plate  to  the 
right  or  to  the  left,  so  that  the  desired  position  may  be  obtained.  By 
opening  the  slit  we  can  make  the  other  end  of  its  image  coincide  with 
the  pole  of  the  other  optic  axis  in  the  interference  image.  This 
position  is  represented  in  Fig.  1. 

The  scale  shows  the  length  of  the  opening  of  the  slit,  and  the 
distance  of  the  poles  of  the  optic  axes.  Measuring  by  the  same 
method  the  distance  of  the  poles  for  mica,  of  which  the  apparent  angle 
of  the  optic  axes  is  known,  the  proportion  is  found  of  the  two  distances, 
which  enables  us  to  calculate  easily  the  angle  of  the  optic  axes.  The 
scale  is  carefully  graduated  in  fifths  of  a  millimetre,  and  with  the  help 
of  a  lens  the  third  of  a  degree  can  easily  be  distinguished,  and  the 
error  in  the  results  is  found  not  to  exceed  one  or  two  degrees. 

It  will  be  understood  that  this  method  is  only  applicable  to 
minerals  in  which  the  angle  of  the  optic  axes  is  not  large,  or  the 
poles  of  the  axes  would  be  no  longer  visible.  But  it  is  easy  to  put 
the  preparation  in  a  small  cup  of  oil,  and  then  measure  the  angle 
in  the  oil. 

Artificial  Crystals  of  Gold. — A  few  years  ago  some  objects  from 
America  were  exhibited  which,  under  a  power  of  150  to  200,  looked 
like  microscopic  fern-leaves  gilt  (see  woodcut),  but  which  were  stated 
to  be  crystals  of  gold.     The  process  by  which  they  were  produced  was 

VOL.  II.  o 


194  NOTES    AND    MEMORANDA. 

not  disclosed,  and  several  ineifectual  attempts  were  made  to  reproduce 

them.  The  following  is  stated  to  be  the  method  of  manufacture  :  * — 
A  solution  of  chloride  of  gold  and  ammonium 
is  placed  in  a  shallow  dish  coated  with  heavy  gold 
foil,  which  is  connected  with  the  zinc  plate  of  a 
large  Daiiiell's  battery.  Near  the  top  of  the  solu- 
tion, and  connected  with  the  copper  plate  of  the 
battery,  a  roll,  made  up  of  thin  strips  of  pure  gold, 
is  susj^ended,  enclosed  in  a  muslin  bag.  The 
strength  of  tho  battery  current  is  controlled  by  a 
»»  coil  of  wire  arranged  as  a  rheostat,  a  clamp  ter- 
minating one  of  the  battery  wires  enabling  the 
operator  to  include  a  greater  or  less  number  of 
coils  in  the  circuit.  The  necessary  conditions 
being  fulfilled,  on  completing  the  circuit  the  gold 
is  gradually  dissolved  from  the  roll  and  deposited 
on  the  bottom  of  the  dish  in  bright  crystalline 

flakes,  having  the  appearance  of  feathers  or  fern-leaves  when  examined 

under  the  Microscope. 

The  Vertical  Illuminator. — This  illuminator  was  originally  in- 
tended to  be  used  in  conjunction  with  medium-power  dry  objectives, 
of  moderate  angles,  such  as  were  formerly  so  much  in  vogue.  Mr. 
Morehouse,  a  well-known  microscopist  of  Wayland,  New  York,  has 
found  that  by  the  conjoint  use  of  the  illuminator  with  immersion 
objectives  of  high  balsam  apertures,  astonishing  results  may  be 
secured ;  as,  for  instance,  the  resolution  of  the  markings  of  Podura 
and  other  insect  scales,  the  striation  of  valves  of  Frustulia  Saxonica, 
Surirella  gemma,  and  similar  "  difficult  "  diatoms,  under  amplifications 
of  3000  and  4000  diameters,  and,  as  a  matter  of  course,  by  reflected 
light. 

Dr.  Edward  Smith  has  devised  a  modification,!  consisting  of  an 
adjustable  shutter,  regulating  the  admission  of  light,  thus  greatly 
improving  the  brilliancy  of  the  objects,  accompanied  Avith  marked 
increase  of  resolving  power ;  and  with  the  instrument  thus  modi- 
fied he  had  no  difficulty  in  obtaining  beautiful  displays  of  the 
Nobert  19th  band,  the  simultaneous  exhibition  of  the  long  and  trans- 
verse strife  of  Frustulia  Saxonica,  &c.,  under  powers  of  3000  ^nd 
4000  diameters. 

Desiring  to  test  it  on  histological  preparations,  he  thus  examined 
a  slide  of  human  blood,  improvised  for  the  occasion,  and  was  asto- 
nished to  find  about  three-fourths  of  the  red  corjjuscles  nucleated. 
The  amplification  employed  in  these  observations  was  about  3700 
diameters. 

A  point  which  should  not  be  lost  sight  of  is  that  the  vertical 
illuminator  can  only  be  successfully  used  in  conjunction  with  an 
objective  of  high  balsam  angle. 

*  Mr.  A.  H.  Chester,  in  'Amer.  Journ.  of  Sci.  ami  Arts,'  3rd  ser.,  vol.  xvi. 
(1878)  p.  29. 

t  'American  Naturalist,'  vol.  xiii.  (1879)  p.  137. 


NOTES   AND    MEMORANDA.  195 

Heproduction  of  Noctiluca.  —  At  p.  331  of  vol.  i.  we  quoted 
from  '  Comptes  Eendus '  a  paper  by  Professor  Cb.  Eobin  on  tbis 
subject.  Tbe  furtber  detailed  memoir  tbere  mentioned  is  publisbed 
in  tbe  autbor's  '  Journal  de  I'Anatomie  et  de  la  Pbysiologie,'  *  wbere, 
besides  tbe  greater  completeness  of  tbe  text  (67  pp.),  it  bas  tbe  advan- 
tage of  being  accompanied  by  seven  plates. 

*  '  Ann.  and  Mag.  Nat.  Hist,,'  ser.  5,  vol.  xiv.  p.  5G3 


o  2 


(     196     ) 


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great  depths  of  the  Sea.  M.  A.  Milne-Edwards.  (From 'Comptes  Rendus.' ^ — 
On  the  Termination  of  the  Visceral  Arterioles  of  Arion  rufus.  M.  S.  Jourdain. 
(From  'Comptes  Rendus.'j — The  Eye  in  the  Cephalopoda.  Prof.  S.  Richiardi. 
(From  '  Soc.  Toscana  di  Sci.  Nat.') 

Grevillea,  Vol.  VII.,  No.  43  (March)  :— 

British  Sphajriacei.     M.  C.  Cooke  and  C.  B.  Piowright. 

Recent  Experiments  by  Dr.  Minks  :  "  Lichens  not  parasitical  Fungi  or 
Algaj."     (From  '  Revue  Mycologique.') 

Diseases  of  Plants  caused  by  Peronospoi'a;,  Mode  of  Treatment,  &c.  Dr. 
Maxime  Cornu.     (From  '  Comptes  Rendus.') 

Some  Exotic  Fungi.     M.  C.  Cooke. 


198  BIBLIOGRAPHY. 

New  British  Lichens.     Communicaterl  by  the  Eev.  J.  M.  Crombie,  F.L.S. 
Two  Species  of  Peronospora.     Prof.  Passerini. 

The  Maple  Disease  {Rhytisma  acerinum).  Dr.  Maximo  Cornu.  (From 
'  Comptes  Eendiis.') 

Califovnian  Fungi.     M.  C.  Cooke. 

The  Dnal-lichcn  Hypotliesis. 

Lichen  Flora  (Eev.  W.  A.  Leighton's). 

Observations  on  some  Species  of  Neapolitan  Fungi.     Dr.  O.  Comes. 

Micogrnphia. 

Addenda  and  Corrigenda  to  New  Diatoms  by  Prof.  P.  T.  Cleve. 

Cryptogamic  Litirature. 

Hardwicke's  Science-Gossip,  No.  170  (February)  : — 
Hints  for  the  Young  Microscopist.    T.  E.  I.     (2  woodcuts.) 
On  the  Colours  of  Animnls  and  the  arrangement  of  Pigment  in  Lepidoptera. 
A.  M.  McAldowie,  M.B.,  CM.     (6  woodcuts.) 

Mia-cscop'/. — A  Live  Box    (Albert  Smith — 2   woodcuts). — Newcastle  Micro- 
scopical Society. — The  Pygidium  of  Insects. 
No.  171  (March)  :— 

Note  on  Preparing  and  Preserving  delicate  Organisms.  G.  du  Plessis  (trans- 
lated by  W.  H.  Dalton). 

Physiological  Character  of  Fenestella  {continued).    G.  E.  Vine.  (II  woodcuts.) 
On  Mounting  and  Preserving  the  Larvse  of  Butterflies  and  Moths.     William 
Brewster. 

Alicroscopii,  Zoology,  Notes  and  Queries. — Cavities  in  Quartz.  (J.  Clifton  Ward.) 
—  A  Novel  Air-pump  for  removing  Air-bubbles  in  Slides.  (Woodcut.)  (A. 
Smith.) — How  to  remove  Canada  Balsam  from  Slides.  (S.  C.  Hincks.) — New 
Forms  of  Camera  Lueida.  (Woodcut.)  (F.  Kitton.) — This  Joiiriial. — Glyciphagtts 
plumiger.  (A.  D.  Michael — J.  Lambert.)  —  Division  of  the  Pteropoda. — 
Fermentation. — Anemones  in  Aquaria.  (G.  L.  B.)— A  curious  Crustacean. 
(Junior.) 

Midland  Naturalist,  Vol.  II.,  No.  14  (February) : — 

Microscopy. — Postal  Microscopical  Society. — Mr.  T.  Bolton's  Microscopical 
Agency. 

Correspondence.— ^wovi  Crystals. — Fresh-water  Polyzoa. — Eotifers,  &c. 
No.  15  (March)  :— 

The  Predaceous  Water-Beetles  (Hydradephaga)  of  Leicestershire.  G. 
Eobson. 

Parasites  of  Man.     T.  Spencer  Cobbold,  M.D.,  F.E.S.,  &c. 

A  Lepidopterist's  Notes  on  the  Season  of  1878.     J.  Anderson,  jun. 

Microscopy.,  ^c. — Micro  fungi  and  other  Microscopical  Preparations  of  Eev.  J. 
E.  Vize. — Snow  Crystals  imder  the  Microscope. — Mounting  Polyzoa  and  Eotifers. 
— Microscopic  Camera-obscura,  &c. 

Reports  of  Societies. 

Monthly  Journal  of  Science,  Third  Series,  Vol.  I.,  No.  62 
(February)  : — 

Compound  Achromatic  Microscope  (Mr.  J.  Browning's).     (1  woodcut.) 

Zentmayer's  roversable  Diatom  Stage. 

No.  63  (March)  :— 

Spider's  Web  for  Micrometers.  (W.  M.  Williams,  in  '  Journal  of  the  Society 
of  Arts.') 

Notes. — Biology. — Physics  (Camera  Lueida  and  Weber's  Slide,  in  this  Journal, 
vol.  ii.  part  1. — 3  woodcuts — &c.).  • 

Nature,  Vol.  XIX.  :— 

January  16: — Biological  Note:  On  the  Eelations  of  Ehabdopleura.  February 
6:  —  A  Zoological  Laboratory. —  Biological  Notes.  —  Cuspian  Sea  Algae.  —  On 
Sprouting  in  Isoetes. — The  Brittle  Stars  of  the  'Challenger.' — Spines  of  the  Echini. 
February  13:— Eesearch  under  Difficulties.     February  20  : — Letter  to  the  Editor: 


BIBLIOGEAPHY.  199 

The  Gulf-weed  (Sargasswn  hacciferum)  a  means  of  Migration  for  Fishes  and 
Marine  Invertebrates  (J.  M.  Jones). — Sir  John  Lubbock  on  Ants.  February  27  : 
— Biological  Notes. — Dredging  Operations,  Gulf  of  Mexico. — Asparagin  in  Plants. 
March  6 : — The  Morphology  of  the  Echinoderms. 

Journal  of  the  Linnean  Society  (Zoology),  Vol.  XIV.,  No.  77 
(issued  31st  January)  : — 

!  On  the  Asteroidea  and  Echinoidca  of  the  Korean  Seas.  W.  Percy  Sladen, 
F.L.S.,  F.G.S.     (1  plate.) 

On  some  Ophiuroidea  from  the  Korean  Seas.  Prof.  P.  Martin  Duncan,  M  B. 
(Lond.),  F.E.S.,  &c.     (3  plates.) 

The  Anniversary  Address  of  the  President,  Prof.  Alltuan,  M.D.,  LL.D., 
F.R.S. — Recent  Progress  in  our  Knowledge  of  the  Structm'c  and  Development 
of  the  Phylactolasmatous  Polyzoa. 

Tbansactions  op  the  Linnean  Society,  Second  Series,  Botany, 
Vol.  I.,  Part  6  (January) : — 

On  Mycoiden  parasitica,  a  new  Genus  of  parasitic  Algae,  and  the  part  which  it 
plays  in  the  formation  of  certain  Lichens.  D.  D.  Cunningham,  M.B.,  F.L.S., 
Surgeon  H.M.  Indian  Army.     (2  plates.) 

On  the  occurrence  of  Conidial  Fructiiication  in  the  Mucorini,  illustrated  by 
Choanepftora .     By  the  same  author.     (1  jilate.) 

On  the  Self-fertilization  of  Plants.  Eev.  George  Henslow,  M.A.,  F.L.S 
F.G.S.     (1  plate.) 

List  of  Fungi  from  Brisbane,  Queensland,  with  Descriptions  of  New  Species. 
Eev.  M.  J.  Berkeley,  M.A.,  F.L.S. ,  and  C.  E.  Broome,  F.L.S.     (2  plates.) 

Proceedings  of  the  Eoyal  Institution  of  Gkeat  Britain, 
Vol.  VIIL,  Part  4,  No.  67  (January,  1878)  :— 

Eecent  Eesearrhes  into  tlie  Origin  and  Development  of  Minute  and  Lowly 
Forms  of  Life,  with  a  glance  at  the  bearing  of  these  upon  the  origin  of  Bacteria. 
Eev.  W.  H.  Dallinger,  F.R.M.S. 

Evolution  of  Nerves  and  Nervo-Systems.     G.  J.  Eomanes,  M.A.,  F.L.S.,  &e. 

Researches  on  the  Deportment  and  Vital  Eesistance  of  Putrefactive  and  In- 
fective Organisms  from  a  physical  point  of  view.  Prof.  Tyndull,  LL.D.,  D.C.L., 
FES 

Part  5,  No.  68  (April,  1878).     (Nil.) 

Proceedings  of  the  Koyal  Society,  Vol.  XXVIII.,  No.  191  : — 

On  the  Influence  of  Light  upon  Protoplasm.  Arthur  Downes,  M.D.,  and 
Thomas  P.  Blunt,  M.A.  Oxon. 

Note  on  the  Influence  exercised  by  Light  on  Organic  Infusions.  John 
TyndaU,  D.C.L.,  F.E.S. 

Eeport  on  Phyto-Palseontological  Investigations  generally,  and  on  those  re- 
lating to  the  Eocene  Flora  of  Great  Britain  in  particular.  Dr.  Constantin  Baron 
Etting.^hausen,  Professor  in  the  University  of  Graz,  Austria. 

No.  192  :— 

On  some  Points  connected  with  the  Anatomy  of  the  Skin.  George  Thin, 
M.D.     (1  plate  and  4  figs.) 

On  Hyaline  Cartilage,  and  Deceptive  Appearances  produced  by  Reagents,  as 
observed  in  the  Examination  of  a  Cartilaginous  Tumour  of  the  Lower  Jaw. 
George  Thin,  M.D.    (5  figs,  of  a  plate.) 

On  the  Etfect  of  strong  Induction-Currents  upon  the  Sti'uoture  of  the  Spinal 
Cord.  W.  M.  Ord,  M.  D.,  F.L.S.,  FeUow  of  the  Eoy.  Coll.  of  Physicians,  Physician 
to  St.  Thomas's  Hospital. 

Concluding  Observations  on  the  Locomotor  System  of  Medusae.  George 
J.  Eomanes,  M.A.,  F.L.S'. 

Transactions  of  the  Zoological  Society,  Part  11 : — 
On  the  Mechanism  of  the  Odontophore  in  certain  MoUusca.     Patrick  Geddes. 
(3  plates.)  


200  BIBLIOGRAPHY. 

Scotland. 

Scottish  Naturalist,  Vol.  V.,  No.  33  (January,  1879) : — 

Supplementary  List  of  Fungi  found  within  the  province  of  Moray.  Rev.  J. 
Keith. 

Description  of  new  Scottish  Lichens.     J.  Stiiton. 

Report  of  Cryptogamic  Society's  Exhibition  of  Fungi,  1878.  Eev.  J. 
Stevenson. 

Ireland. 

Pkoceedings  of  the  Eoyal  Irish  Academy,  Vol.  III.,  Ser.  II., 
No.  2  (November)  : — 

On  Hullite — a  liitherto  unrlescribed  Mineral,  &c.  Edward  T.  Hardman, 
F.C.S.,  H.M.  Geol.  Survey.  With  Notes  on  the  Microscopical  Appearances,  by 
Prof.  E.  Hull,  M.A.,  F.R.S. 

Transactions  of  the  Eotal  Irish  Academy,  Vol.  XXVI. 
(Science),  No.  17  (October)  :— 

Report  on  the  Acanthology  of  the  Desmosticha  (Haeckel).  Part  I.  On  the 
Acanthological  RL-lations  of  the  Desmostic-ha.  H.  W.  Mackintosh,  B.A.,  Senior 
Mod.  in  Nat.  Sc,  T.C.D.     (3  plates.) 


Australian  Colonies. 

Proceedings  of  the  Linnean  Society  of  New  South  Wales, 
Vol.  II.,  Parts  3  and  4  (issued  1878):— 

On  some  Australian  Shells,  described  by  Dr.  A.  Gould.  Eev.  J.  E.  Tenison- 
Woods,  E.G. S.,  &e.,&c. 

On  some  new  Marine  Shells.     By  the  same  author. 

Descriptions  of  three  new  Species  of  Helix  from  South  Australia.  Prof.  Ralph 
Tate. 

On  the  Extra-tropical  Corals  of  Australia.  Rev.  J.  E.  Tenison- Woods, 
F.G.S.,  F.L.S.,  &c.,  &c.     (.S  plates.) 

On  the  Echini  of  Australia  (Supplemental  Note).     By  the  same  author. 

Continuation  of  the  Mollusca  of  the  Chevat  Expedition.  J.  Brazier,  CM  Z.S., 
Corr.  Memb.  Roy.  Soc,  Tas. 

Notes  and  Remarks  on  Mollusca  recently  found  in  Port  Jackson,  and  New 
Caledonia.     By  the  same  author. 
Vol.  III.,  Part  1  :— 

On  an  Australian  variety  of  Neritina  puUige?-a,  Linn.  Rev.  J.  E.  Tenison- 
W^oods,  F.G.S.,  F.L.S.,&c. 

On  a  new  Genus  of  Milleporidsa.     By  the  same  author. 

On  a  new  Species  of  Psammoseris.     By  the  same  author.     (1  plate.) 

On  a  new  Species  of  Desmophyllum  (Z>.  quinarium).  and  a  young  stage  of  Cyclo- 
seris  sinerisis.     By  the  same  author. 

On  some  Australian  Littorinidse.     By  the  same  author. 

On  the  Power  of  Locomotion  in  the  Tunicata.     William  Maclcay,  F.L.S. 

Journal  and  Proceedings  of  the  Eoyal  Society  of  New  South 
Wales,  1877,  Vol.  XI.  (issued  1878)  :— 

On  some  now  Avistralian  Polyzoa.  Rev.  J.  E.  Tenison- Woods,  F.G.S. ;  Hon. 
Mcmb.  R.  S.  N.S.W.,  &c.,  &c.     (2  woodcuts.) 

On  some  Australian  Tertiary  Corals.    By  the  same  author. 

A  Synopsis  of  the  known  species  of  Australian  Tertiary  Polyzoa. 
R.  Etherid.se,  jun.,  F.G.S.,  &c. 

Ji'cports  from  the  Sections  {in  Abstract). — Section  E.  Micro.scopical  Science. — 
Reports  of  Proceedings  of  May-Nov.  Meetings. 

Remarks  on  the  Coccus  of  the  Cape  Mulberry.  F.  Milford,  M.D.,  M.R.C.S., 
&c. 

Notes  on  some  Local  Species  of  Diatomacese.     G.  D,  Hirst. 


BIBLIOaRAPHY.  201 

Transactions  and  Proceedings  of  the  Eoyal  Society  of 
Victoria,  Vol.  XIV.  (issued  lltli  July,  1878):— 

On  some  new  Marine  MoUusca.  Rov.  J.  E.  Tenison-Woods,  F.G.S.,  F.L.S., 
&c. 

On  the  History  of  Palaeozoic  Actinology  in  Australia.  R.  Etheridge,  jun., 
F.G.S. 


United  States. 
American  Journal   of  Microscopy,    Vol.    III.,    No.    12    (De- 
cember) : — 

What  can  be  done  -with  a  Cheap  Microscope.     (From  '  Young  Scientist.') 

The  Microscope  in  Medicine.     Dr.  S.  M.  Mouser. 

The  Use  of  the  Microscope.  Geo.  E.  Blackham,  M.D.  (From  '  Cincinnati 
Medical  News.') 

The  Microscopical  Examination  of  Yeast  popularly  explained.  (From 
'  London  Brewers'  Journal.') 

Outlines  of  a  Process  for  the  Examination  of  Urine  for  Medical  Purposes. 
AiTanged  by  R.  Hitchcock. 

On  Biotite  as  a  Pseudomorph  after  Olivine.     Prof.  A.  A.  Julien. 

Recent  Progress  in  the  Study  of  the  Lower  Order  of  Cryjjtogams  (Sir  Joseph 
Hooker's  Presidential  Address,  R.  S.). 

Exclusive  Publication  of  Society's  'Proceedings.' 

The  Micrometric  Standard. 

Review  of  Kings  '  Urological  Dictionary.' 

Melting  Point  of  Fats. 
Vol.  IV.,  No.  1  (January)  :— 

Structure  of  Coloured  Blood-corpuscles.  (Paper  read  before  the  'New  York 
Academy  of  Sciences,'  by  Prof.  Elsberg,  M.D.)     (1  plate.) 

Artificial  Crystals  of  Gold  and  Silver.     Albert  H.  Chester.     (5  woodcuts.) 

Trichinae  in  Pork.  (Report  of  Mr.  Atwood  and  Dr.  Beltield  to  Office  Health 
Depart.,  Chicago.) 

Tiie  Microscope  in  Medical  Jurisprudence.  (Paper  read  by  President  H.  C. 
Hyde  before  the  'San  Francisco  Microscopical  Soi'iety.') 

Notes  on  Diatomaceae  from  Santa  Monica,  California.  (Paper  by  Mr.  Chas. 
Stodder,  read  before  the  same  Society.) 

Microscopic  Soire'es. — An  improved  Method  of  exhibiting  Objects.  Geo.  E 
Fell. 

A  new  Form  of  Collecting  Cane.    (1  woodcut.) 

Microscopic  Pond  Life.  (Paper  read  before  the  North  Staffordshire  (Eng.) 
Naturalists*  Field  Club,  by  Mr.  T.  S.  Wilkins.) 

Transactions  of  Societies. —  San  Francisco  Microscopical  Society,  Nov.  7  and  2L 
— Microsco[iical  Section,  Troy  Scientific  Association  (no  date). — Buffalo  Micro- 
scopical Club  (Nov.  10  and  11). 

Exchanges. 

A  new  Rotifer.     D.  S.  Kellicott.     (1  woodcut.) 

Volvox  glohator.     (From  '  Young  Scientist.)     (1  woodcut.) 

Sizes  of  Gun  Punches. 

Tolles'  ^V  Objective. 

Trichina. 

Transactions  of  Societies.—  San  Francisco  Microscopical  Society,  Dec.  5  and  19. 

Buffalo  Microscopical  Club,  Jan.  14. 

Exchanges. 

American  Journal  of  Science  and  Arts,  Third  Series,  Vol 
XVII.,  No.  97  (January)  :— 

Scientific  Intelligence. — Botany  and  Zoology  : — '  Die  Algen  Flora  des  Weissen 
Meeres.'  By  Dr.  C.  Gobi. — 'North  American  Fungi:  Fungi  Americani,  Ctntu- 
ries  I.  and  IL'  By  H.  W.  Raveuel  and  M.  C.  Cooke. — '  Nortli  American  Fuuo-i  ' 
By  J.  B.  Ellis.—'  The  Early  Types  of  Insects.'    By  S.  H.  Scud  ler.  °  " 


202  BIBLIOGRAPHY. 

No.  98  (February)  :— 

SckntifiG  IntcUujcnce. — Botany: — Botanical  Necrology  of  1878 — E.  M.  Fries 
(Upsal);  L.  Pfeiffer  (Cassel)  ;  A.Murray  (Edinburgh);  A.  Bloxam  (England) ; 
F.  V.  Raspail  (Paris)  ;  S.  Kurz (Calcutta);  M.  Durieu  (Bordeaux) ;  C.  Pickering 
(Boston,  U.S.);  M.  Seubert  (Carlsvuhe) ;  T.  Thomson  (England);  G.  Zunardini 
(Venice);  E.  de  Visiani  (Padua);  B.  C.  Du  Mortier. 

American  Naturalist,  Vol.  XIII.,  No.  1  (January)  : — 

On  certain  Contrivances  for  Cross-Fertilization  in  Flowers.  By  Prof.  J.  E. 
Todd.     (8  woodcuts.) 

The  Gemmule  v.  the  Plastidule  as  the  ultimate  Physical  Unit  of  Living 
Matter.     J.  A.  Ryder. 

Absorption  of  Water  by  the  Leaves  of  Plants.  A.  W.  Bennett,  M.A.,  B.S., 
F.L.S. 

Recent  Literature, — Sars'  Molluscan  Fauna  of  Arctic  Norway  (W.  H.  Dall). 
— Packard's  Guide  to  the  Study  of  Insects. — Thomas's  Noxious  Insects  of 
Illinois. 

General  Notes. — Zoology: — Amphioxus  and  Lingula  at  the  Mouth  of  Chesa-- 
peake  Bay.— Singular  Habit  of  a  Meloid  Beetle  (S.  W.  Williston).— New  Car- 
cinological  Papers. — CoUett's  Li>t  of  Norwegian  Zoological  Literature  for  1877. 

Microscopy. — Removal  of  Air  from  Microscopic  SiJecimens  (F.  C.  Clark). — 
Limits  of  Accuracy  in  Measurements  with  the  Microscope  (W.  A.  Rogers,  from 
a  paper  read  at  the  Nat.  Micr.  Congress).— The  Society  Screw. — Exchanges. 

No.  2  (February)  : — 

Instinct  and  Reason.     F.  C.  Clark,  M.D. 

Recent  Literature. — Brehm's  Animal  Life.     (11  plates.) 

Moseley's  Structure  of  tlie  Stylasteridse. 

General  Notes.— Zoology:— A  Gall -inhabiting  Ant  (W.  H.  Patton).— A 
Hummers  Meal  (W.  H.  Ballou). — Recent  Papers  on  Crustacea  (J.  S.  King-sley). 
— The  Nebaliad  Crustacea  as  Types  of  a  new  Order  (A.  S.  Packard,  jun.). 

Microscopij. — Nucleated  Red  Corpuscles  of  Human  Blood  (^J.  Edwards  Smith). 
— The  Wenhain  Compressorium. — Exchanges. 
No.  3  (March)  :— 

Remarks  on  Fossil  Shells  from  the  Colorado  Desert.  R.  E.  C.  Stearns.  (12 
woodcuts.) 

Experiments  with  Pyrethrum  roseum  in  killing  Insects.  W.  L.  Carpenter, 
U.S.A. 

Recent  Literature.  —  Gegenbaur's  Elements  of  Comparative  Anatomy. — 
Schmarda's  Zoology. 

Botany. — Asp'dium  hoottii. 

Geology  and  Fakeontology. — The  Nature  of  Eozoon. 

Microscopy. — New  Microscopical  Societies. — American  Quarterly  Microscopical 
Journal.— Sale  of  a  Microscopical  Library. — Spring  Clips. 

Amerioan  Quarterly  Microscopical  Journal,  Vol.  1.,  No.  2 
(January) : — 

New  Rhizopods.     Prof.  W.  S.  Barnard,  B.S.,  Ph.D.     (1  plate.) 

A  Study  of  one  of  the  Distomes.     C.  H.  Stowell,  M.D.     (1  plate.) 

On  the  probable  Error  of  Micrometric  Measurements.  Edward  W.  Morley, 
M.D.,  Ph.D. 

Standard  Measures  of  Length.     Prof.  W.  A.  Rogers. 

On  the  Fissure-Inclusions  in  the  Fibrolitic  Gneiss  of  New  Rochelle.  Alexis 
A.  Julien.    (1  plate  and  1  woodcut.) 

Tlie  Classification  of  the  Algse.     Rev.  A.  B.  Hervey,  A.M.     (1  plate.) 

The  Ampulla  of  Vater,  and  the  Pancreatic  Ducts  in  the  Domestic  Cat.  Simon 
H.  Gag.^  B.S.     (1  plate.) 

Practical  Hints  in  Preparing  and  Mounting  Animal  Tissues.  Carl  Seller, 
M.D.     (2  woodcuts.) 

Observations  on  several  Forms  of  SaprolegniesB  {concluded).  Frank  B.  Hine,  B.S. 

Classification  of  the  simplest  Forms  of  Life.     B.  f^yferth. 

Editorial. 

Microscopic  Vision.— Yellow  Fever. — A  Letter  from  Professor  Abbe— Notes. — 


BIBLIOGEAPHY.  2('3 

Laboratory  Notes  and  Queries  (by  S.  H.  Gage"'. — Digest  of  current  Liteiatiire. 
— Microscopical  Societies. — Book  Notices. — Publications  received. 

Transactions  of  the  Xeic  York  Microscopical  Socictf/  (January,  1S79\ 

Mechanism  by  which  Echmorhynchus  anchors  his  Snout.     J.  D.  Hyatt. 

Euglena  and  Trachelomonas.     E.  Hitchcock. 

Proceedings  of  Meetings  of  4th  Ojt.  and  1st  and  13th  Nov.,  1S78. 


France. 

Annales  des  Sciences  Natukelles  (Botanique),  Sixth  Series, 
Vol.  VII.,  Nos.  1  and  2  (issued  February,  1879)  :— 

Kesearches  on  the  Depazese.     L.  Crie'.     (8  plates.) 

Studies  on  the  Seminal  Integuments  of  the  GymnospeiTQOUS  Phanerogams. 
C.  E.  Bertrand      (6  plates  to  follow.) 

Observations  on  the  Modifications  of  Plants  according  to  tlie  physical  con- 
ditions of  tlie  medium.     G'.  Bonnier  and  Ch.  Fh^liault. 

Brebissoxia, — illustrated  MontUy  Review  of  Algology  and  Botani- 
cal Micrograpty.   Edited  by  M.  G.  Hubersou.  Vol.  1.,  No.  7  (January)  : 

Spii-ogyra  Lutetiana,  n.  sp.,  P.  Petit.     P.  Petit,     d  plate.) 

Some  Remarks  ou  the  Diatomacese  of  P.  T.  Cleve  and  Moller.  Upsal,  1878. 
Nos.  1-48.     A.  Grunow.     (From  '  Amer.  Journ.  of  Microscopy.') 

Diseases  of  Plants  caused  by  Peronospora,  &c.  Disease  of  Lettuces  called  "  Le 
Meunier."     (Both  by  Max  Cornu  and  from  '  Comptes  Eendus.') 

Organization  of  IJygrocrocis  arsenicus,  Bre'b.  (By  Prof.  L.  Marchand,  from 
'  Comptes  Eendus.') 

Bibliography. —  The  Thallus  of  the  Diatomacese.  Dr.  M.  Lanzi. — ffidogoniaj 
Americanje  of  V.  B.  Wittrock.     A'cws. 

Journal  de  l'Anatomie  et  de  la  Physio logie  de  l'Homme  et 
DES  Animaux,  Vol.  XV.,  No.  1  (January  and  February)  : — 
Embryogeny  of  Astcriscns  vcrruculatus.     Dr.  J.  Barrois.     (2  plates.) 
Evolution  and  Structure  of  the  Nuclei  of  the  Elements  of  the  Blood  in  the 
Triton.     G.  Pouchet.     (1  plate.) 

Study  ou  the  Lymphatics  of  the  Skin.    Drs.  G.  and  F.  E.  Hoggan.     (2  plates  ) 
Anulysis  of  'Tlie  Absorption  of  Colouring  Matters  by  the  Eoots  of  Plants.' 
MM.  Max  Cornu  and  E.  Mer. 

No.  2  (March  to  April)  :— 

The  Parasitic  Acarians  of  the  Cellular  Tissue  and  Air  Reservoirs  of  Birds. 

P.  Me'guin.     (2  plates  and  3  woodcuts.) 

Contribution  to  the  Study  of  the  Bctimil  Purple.  M.  H.  Beauregard.    (1  plate.) 
On  the  Employment  of  Wet  Collodion  for  Microscopic  Sections.    Mathias 

Duval. 

Journal  de  Microgkaphie,  Vol.  II.,  No.  9  (September) :  * — 

Rente. — The  National  Congress  of  American  Microscopists  at  Indianapolis. — 
Standard  for  Micrometric  Measurements.  —  Various  American  (and  Anglo- 
American)  Books  on  the  Microscope,  and  American  Microscopical  and  other 
Journals. 

Migration  of  Blood-corpuscles  in  passive  Hypersemia.  Dr.  W.  T.  Belfield. 
(Read  at  the  Indianapolis  Congress.) 

A  New  Field  for  the  Microscopist  (^concluded).     W.  Saville  Kent. 

Studies  on  the  Schizomycetes,     Oscar  Brefeld. 

National  Micrograph ical  Congress  at  Indianapolis.     Dr.  J.  Pelletau. 

No.  10  (October)  :*— 

Fevue. — M.  G.  Huberson's  '  BreT^issonia '  and  'Practical  Formulary  of  Photo- 
graphy with  Silver  Salts. ' — The  '  Zeitschrift  fur  Mikroskopie,'  and  otlier  German 
and  Axnerican  Joui-nals. 

*  For  some  reason  which  is  unexplained,  neither  of  these  numbers  were  sent  to 
the  subscribers  in  this  country,  and  it  was  not  until  No.  1 1  appeared  that  the 
omission  was  discovered. 


204  BIBLIOGRAPHY. 

The  Lymphatic  Hearts  (continuation').     Prof.  RanviL-r.     (1  phxte.) 

Preliiuiuary  Note  on  the  Development  of  the  Blood  and  tlie  Vessels  (^conclu- 
sion').    Drs.  V.  Brigldi  and  A.  Tafani. 

Vulvox  (jlobator.  A.  W.  Bennett.  (From  'Am.  Jour,  of  Mic'  and  'Pop.  Sc. 
Rev.') 

New  Oil-Immersion  Objective  of  C.  Zeiss,  of  Jena.  W.  H.  Dallinger.  (Taken 
from  '  Nature,'  vol.  xviii. ) 

Micro  copical  Technic. — Preparation  of  whole  Insects  without  pressure  for  the 
Binocular.     S.Green.     (From  '  Jour.  Quekett  Mic.  Club.') 
Vol.  III.,  No.  1  (January)  :— 

Revue. — The  'Revue  des  Sciences  Naturelles'  of  Montpellier. —  The  '  Recueil 
de  Me'de'cine  Ve'te'rinaire.' — The  '  Bulletin  de  la  Socie'te  Beige  de  Microscopie,' 
and  American  Journals. 

The  Muscles  of  the  CEsopliagus.     Prof.  Ranvier. 

Researches  on  Speimatogenesis  studied  in  some  pulmonate  Gasteropoda.  Dr. 
M.  Duval.     (1  plate.) 

Angular  Aperture  of  Microscope  Objectives  (continuation).  Dr.  G.  E.  Black- 
ham.     (1  plate.) 

Diatoms  of  the  Archipelago  of  the  West  Indies  (^continuation).  Prof.  P.  T. 
Cleve.     (12  woodcuts.) 

Histological  Microscope  of  Mr.  C.  Collins.     (1  woodcut.) 

On  the  Formation  of  the  Spores  of  the  Mesocarpese.  E.  Perceval  Wright. 
(From  '  Nature,'  vol.  xviii.) 

Bibliography. — Researches  of  M.  Van  Tieghcm  on  the  Mucoriui.  By  A. 
Faure. 

No.  2  (February)  :— 

Revue. — Diatoms— Max  Cornu  on  Peronospora. — 'Revue  Mycologique.' — The 
Pasteur-Berthelot  Discussion,  &c. — This  Journal,  and  other  English,  American, 
&c.,  Journals. 

Fecundation  in  the  Vertebrates.   'Prof.  Balbiani. 

Angular  Aj^erture  of  Microscope  Objectives  (continued).  Dr.  G.  E.  Blackham. 
(1  plate.) 

Researches  on  Spermatogenesis  studied  in  some  pulmonate  Gasteropoda  (con- 
clusion).     Dr.  Mathias  Duval.     (1  plate.) 

Method  of  Studying  the  Embryo  of  Fishes.  M.  F.  Henneguy.  (From  '  Bull. 
Soc.  Phil.,'  Paris.) 

Diatomaceaj  of  the  West  Indian  Archipelago  (continued).  Dr.  P.  T.  Cleve. 
(14  woodcuts.) 

Note  on  some  Diatoms.  F.  Kitton.  (From  'Bull,  de  la  Soc.  Beige  de 
Micr.') 

Description  of  new  Species  of  Diatomacese.  Prof,  H.  L.  Smith.  (From 
'  Am.  Quart.  Micr.  Journ.') 

Reproduction  of  the  Diatomacese.     (From  this  Journal.) 

Students'  Microscope  of  W.  Watson  and  Sun,  of  London.     (I  woodcut.) 

Royal  Microsco23ical  Society  of  London. 

Cabinet  of  Microscopy  of  Arthur  C.  Cole  and  Son,  of  London. 

A  Letter  from  Dr.  E.  Abbe.     (From  '  Am.  Quart.  Micr.  Journ.') 

Eevue  Mtcologique.  (Edited  by  M.  C.  Eoumeguere.)  Vol.  I., 
No.  1  (January) : — 

Recent  Experiences  of  Dr.  Minks. — Lichens  are  not  "  Fungi  parasitic  on 
Algae."     The  Editor. 

The  Artificial  Cultivation  of  Fungi  in  Japan.     Count  de  Castillon. 

Extraordinary  Case  of  Development  of  Bovista  gigantea,  Ne'es,  in  the  environs 
of  Toulouse.     Tlie  Editor. 

Fuugorum  Novorum  Exoticorum  Decas.     F.  de  Thiimen. 

The  Myxogastres.     Dr.  L.  Que'let. 

The  Common  Names  of  the  Fungi  in  the  environs  of  Saintes  (Chareuto-Infe- 
rieure).     P.  Brunaud. 

Origin  of  the  Genus  Microsphmria,  Leveillc.     The  Editor. 

The  Preservation  of  Fungi  from  a  scientific  point  of  view.    The  Editor. 


BIBLIOGRAPHY.  205 

Microscopic  Studies  and  Preparations  of  Fungi. — Microscopic  Slides  of  the 
Rev.  J.  E.  Vize. — Pliotograpliic  Microscope  of  Dr.  Ch.  Fayel.     The  Editor. 
Tekphora  pahnata,  Fries.     Forina  paradoxa,  Nob,     The  Editor. 
Bibliography. 
News. 

Bulletin  de  la  Societe  Botanique  de  France,  Vol.  XXV.,* 
Parts  A.-D.  :— 

Bibliographical  Summary. 

Part  I.  Catalogue  of  the  Marine  Diatomaccffi  of  the  Bay  of  St.  Brieuc  and 
of  the  Coast  of  the  Cotes-du-Nord  Department.     M.  Leudugt- r-Fortmorel. 

The  Seat  of  the  Colouring  Matters  in  tlie  Seed  (contirmatiun).     M.  J.  Poisson. 

Note  on  three  new  Species  of  Mosses  of  New  Caledonia  belonging  to  the 
Genus  Pterobryella^  C.  Miill.     M.  Em.  Bescherelle. 

CoMPTES  Eendus,  Vol.  LXXXVIII.,  No.  1  (6th  January) : — 

Reply  to  M.  Pasteur.     M.  Berthelot. 

On  a  Giganic  I:Opod  of  the  Deep  Sea.     M.  Alph.  Milne-Edwards. 

On  the  Disease  of  the  Chestnut-trees.     M.  J.  de  Seynes. 

No.  2  (13th  January)  :— 

Do  there  exist  among  the  lower  Organisms  species  exclusively  aerobian  and 
others  anaiirobian,  &e.     M.  Tre'cul. 

Observations  on  the  Communication  of  M.  Trecul,  by  M.  Pasteur. 

Second  Reply  to  M.  Berthelot.     M.  Pasteur. 

The  Polymorphism  of  Agaricus  mellcus,  Vahl.     M.  J.  E.  Planchon. 

New  Observations  on  the  Development  and  Metamorphoses  of  Tsenias. 
M.  P.  Me'gnin. 

No.  3  (20th  January)  :— 

Observations  on  the  Second  Reply  of  M.  Pasteur.     M.  Berthelot. 

Reply  to  the  Notes  of  M.  Tre'cul  of  the  30th  December  and  13th  January. 
M.  Pasteur. 

Reply  of  M.  Trecul. 

Observations  of  M.  Pasteiu". 

On  the  Special  Apparatus  of  Nutrition  of  Phanerogamous  Parasitic  Species. 
M.  Chatin. 

Researches  on  the  Development  of  Ova  and  of  the  Ovai  y  in  Mammals,  after 
birth.     M.  Ch.  Rouget. 

No.  4  (27th  January)  : — 

Third  Reply  to  M.  Berthelot.     M.  Pasteur. 

On  the  Composition  of  the  Banana,  and  on  attempts  at  utilizing  this  Fruit. 
MM.  V.  Marcano  and  A.  Muntz. 

On  the  Termination  of  the  Visceral  Arterioles  of  Arion  rufus.  M.  S.  Jourdain. 

Researches  on  the  Physiological  Action  of  Grenat  or  residue  of  the  manufac- 
ture of  Fuchsine.    M.  Jousset  de  Bellesme. 

On  the  Quantity  of  Light  lost  in  actuating  the  Visual  Apparatus,  and  its 
variations  under  different  conditions.     M.  Cliarpentier. 

On  the  Phosphorescence  of  the  Flesh  of  the  Lobster.  MM.  C.  Bancel  and  C. 
Husson. 

No.  5  (3rd  February) : — 

Remarks  on  the  Third  Reply  of  M.  Pasteur.     M.  Berthelot. 

On  the  Fermentation  of  Cellulose.     M.  Ph.  Van  Tieghem. 

The  Influence  of  Duration  and  Intensity  on  Luminous  Perception.  MM.  Ch. 
Richet  and  Ant.  Breguet. 

The  Intimate  Structure  of  the  Central  Nervous  System  of  Decapod  Crustacea. 
M.  E.  Yung. 

No.  6  (10th  February):— 

Last  Reply  to  M.  Pasteur.     M.  Tre'cul. 

Verbal  Observations  of  M.  Pasteur. 


*  The  publications  of  the  Society  have  been  interrupted  by  a  printer's  strike, 
but  will  soon  be  up  to  date. 


206  BIBLIOGRAPHY. 

Reply  of  M.  Trecul  to  the  Observations  of  M.  Pasteur. 

Reply  of  M.  Pasteur. 

Fourth  Reply  to  M.  Berthelot.     M.  Pasteur. 

Oil  the  Existence  of  a  Prehensile  or  Complementary  Adherent  Apparatus  in 
Parasitic  Plants.     M.  A.  Chatin. 

Researches  on  the  Formation  of  Latex  during  Germinative  Evolution  in  the 
Embryo  of  Tragopocpn  porrifolius.     M.  E.  Faivre. 

Research!  s  on  Beer  Yeast.     MM.  P.  Schiitzenberger  and  A.  Destrem. 

On  the  Banana.     M.  B.  Coren  winder. 

On  different  Epizootics  of  Diphtheria  of  Birds  observed  at  Marseilles,  and  on 
the  possible  Rehitions  of  this  Disease  with  the  Diphtheria  of  Man.     M.  Nicati. 

On  the  Sensibility  of  the  Eye  to  the  action  of  Coloured  Light  more  or  less 
combined  with  White  Light,  and  on  the  Photometry  of  Colours.  M.  A.  Charpentier. 

Researches  on  the  Liver  of  tlie   Oephalopodous  Mollusca.    M,   Jousset  de 
Bellesme. 

Observations  on  a  Rain  of  Sap.     M.  Ch.  Musset. 
No.  7  (17th  February)  :— 

On  the  Respiratory  Innervation  in  the  Octopus.     M.  L.  Fredericq. 

On  the  Functions  of  the  Ganglionic   Chain  in  the   Decapod   Crustaceans. 
M.  E.  Yung. 

No.  8  (24tli  February):— 

On  the  Composition  of  Beer  Yeast.    MM.  P.  Schiitzenberger  and  A.  Destrem. 

On   the   presence  of  a  Segmentary  Organ  in  Endoproct   Bryozoa.     M.  Ij. 
Joliet. 

On  the  Segmentary  Organs  and  the  Genital  Glands  of  Sedentary  Polychpofous 
Aunelides.     M.  L.  C.  E.  Cosmovici. 
No.  9  (3rd  March)  :— 

Reply  to  M.  Van  Tieghem  as  to  the  Origin  of  Amylobacter.     M.  A.  Tre'cul. 

Researches  on  the  Foetal   Envelopes  of  the  Armadillo   with  nine  Bands. 
M.  Alph.  Milne-Edwards. 

Researches  on  Digestion  in  Cephalopod  Molluscs.     M.  Jousset  de  Bellesme. 

Researches  on  Peronospora  gangliiformis  of  Lettuces.     MM.  Bergeret  and  H. 
Moreau. 

On  the  Influence  of  Oxygen  on  Alcoholic  Fermentation   by   Beer   Yeast. 
M.  A.  Be'champ. 

On  a  Method  of  Preserving  Infusoria.    M.  A.  Certes. 


Belgium. 
Bulletins  de  l'Academie  Eoyale  des  Sciences,  des  Lettbes  et 
DES  Beaux- Arts  de  Belgique,  Second  Series,  VoL  XLV.  (January 
to  June,  1878)  :— 

Researches  on  the  Acinetse  of  the  Coast  of  Ostend.  Parts  2-4.  M.  Julien 
Fraipont.     (4  plates.) 

Second  additions  to  the  Synopsis  of  the  Cnrdulinrc,  and  List  of  those  described 
in  the  Synopsis  and  its  two  additions.     M.  Edm.  de  Selys  Longchamps. 

On  a  new  Species  of  Crustacea  of  the  Coalfield  of  Belgium.  Dr.  L.  G.  de 
Koninck  ;  being  a  translation  of  a  paper,  "  Discovery  of  a  Species  of  Brachyuran 
Decapod  in  the  Coalfield  of  the  environs  of  Mens,"  sent  by  Dr.  H.  Woodward, 
F.R.S.,  F.G.S.,  F.Z.S.     (1  plate  and  1  woodcut.) 

Researches  on  the  Development  of  the  Inferior  Jaw-bone  of  Man.  M.  H. 
Masquelin.     (2  plates.) 

Contribution  to  the  Physiology  of  the  Vagus  Nerve  of  the  Frog.  MM.  F. 
Putzeys  and  A.  Swaen. 

Researches  on  the  Venomous  Apparatus  of  the  Ohilopodan  Myriapoda ; 
Description  of  true  Poison  Glands.     M.  Jules  MacLeod.     (1  plate.) 

Vol.  XL VI.  (July  to  December)  :— 

Discovery  of  Brachiopoda  of  the  Genus  Lingula.     M.  C.  Malaise. 

Preliminary  Communication  on  the  Movements  and  the  Innervation  of  the 
Central  Organ  of  Circulation  in  the  Articulated  Animals.     M.  Felix  Plateau. 


BIBLIOaRAPHY.  207 

On  the  Digestion  of  Albuminoids  by  some  Invertebiata.    Dr.  Leon  Frcdericq. 

On  a  Law  of  the  persistance  of  Impressions  in  the  Eye.     M.  J.  Plateau, 
f  Fourth  additions  to   the   Synopsis  of  the  Gomphinse.     M.  de  Selys  Long- 
champs. 

Researches  on  the  Structure  of  the  Digestive  Apparatus  of  the  Mygalce  and 
the  Nephila:.     M.  Valere  Lie'nard.     (1  plate.) 

On  the  Organization  and  Physiology  of  the  Poulp.     Dr.  Le'on  Fredericq. 

Reports  of  MM.  Cre'pin,  Gilkinet,  and  Morren  on  the  two  Memoirs — "  Bryo- 
logia  Belgica  "  and  "  Belgian  Mycological  Flora  " — sent  in  response  to  the  fourth 
question  proposed  for  the  Competition  of  1878. 

Memoires  de  l'Academie  Eoyalb  des  Sciences,  des  Lettres 
ET  DES  Beaux- Arts  de  Belgique,  Vol.  XLII : — 

Analytical  Bibliography  of  the  principal  subjective  Phenomena  of  Vision 
from  ancient  times  to  the  end  of  the  eighteenth  century,  followed  by  a  simple 
Bibliography  for  the  expired  part  of  the  present  century.     M.  J.  Plateau. 

Researches  on  the  Phenomena  of  Digestion  and  on  the  Structure  of  the 
Digestive  Apparatus  in  the  IMyriapods  of  Belgium.  Prof.  Felix  Plateau.  (3 
plates.) 

Bulletin  de  la  Societe  Belge  de  Miceoscopie,  Vol.  V.,  No.  3 : — 

Pioceedings  of  the  Extraordinary  General  Meeting  and  of  the  Monthly  Meeting 
of  26th  December,  1878,  containing : — 

Report  by  M.  Ledeganck  on  forty-eight  mycological  preparations  presented  by 
Dr.  Zimmermann. 

A  word  on  the  Gregarinse,  by  M.  Alex.  Foettinger. 

Notes  of  Micrography,  by  Dr.  H.  Van  Heurck,  No.  III.  The  Camera  Lucida 
of  Dr.  J.  G.  Hofmann.     (4  woodcuts.) 

Analytical  and  Critical  Review  of  O.  Nordstedt's  '  De  algis  aquse  dulcis  et  de 
characeis  ex  insulis  Saudvicensibus  a  Sw.  Berggren  1875  reportatis.' — 'Cleve's 
Diatoms  from  the  West  Indian  Archipelago.' — '  Journal  of  the  Royal  Micro- 
scopical Society,'  No.  6. — Dr.  Hermann  Fol's  '  Commencement  of  Henogeny  in 
various  Animals.' 

No.  4  :— 

Proceedings  of  the  Extraordinary  General  Meeting  of  23rd  January,  and  of  the 
Monthly  Meeting  of  30th  January,  1879  :— 

The  Terrestrial  Diatomacese.     Julien  Deby. 

The  Rivet  Microtome.     M.  Cornet. 

Analytical  and  Critical  Review  of  '  Revue  des  Sciences  Naturelles  de  Mont- 
pellier '  (and  seven  abstracts  of  recent  scientific  papers  contained  in  it). — '  Der 
Organismus  der  Infusionsthiere,'  Part  III.,  of  Dr.  F.  Ritter  von  Stein. — '  Diatoms,' 
Part  III.,  edited  by  P.  F.  Cleve  and  J.  D.  MiJller.' — '  Diatomacearum  Species 
Typicse,'  Cent.  IV.,  by  H.  L.  Smith. — '  Atlas  der  Diatomaceen,'  by  Ad.  Smidt. — 
'Journal  de  Micrographie,'  January,  1879. 


Holland. 
Archives  Neerlandaises  des  Sciences  Exactes  et  Naturelles 
(published  by  the  Dutch  Society  of  Sciences  at  Haarlem),  Vol.  XIII., 
Parts  1-5  :— 

On  the  Determination  of  the  Focal  Distances  of  Lenses  with  short  Foci. 
J.  A.  C.  Oudemans.     (5  figs,  of  a  plate.) 

On  the  Albumen  of  Serum  and  the  Egg,  and  on  its  Combinations.  A. 
Heynsius. 

Comparative  Studies  on  the  Electric  Action  of  the  Muscles  and  the  Nerves. 
Th.  W.  Engelmann. 

On  the  Permeability  of  the  precipitated  Membranes.     Hugo  de  Vries. 

On  the  Influence  of  the  Blood  and  Nerves  on  the  Electro-motor  Power  of  arti- 
ficial transversal  Sections  of  Muscles.    By  the  same  author. 

New  Researches  on  the  Microscopic  Phenomena  of  Muscular  Contraction.  By 
the  same  author.     (1  plate.) 


208  BIBLIOGEAPHY. 

Germany; 
Arohiv    fur    Naturgeschiohte    (Forty-fourth    year),    Vol.    I., 
Part  1  :— 

Developmentof  some  Venezuelan  Butterflies  after  the  Observations  of  GoUmer. 
Dr.  H.  Dewitz.     (1  plate.) 

Minor  Fragments  on  the  Comparative  Anatomy  of  the  Arthropoda.  G.  Haller. 
(1  plate.) 

Contributions  to  the  Natural  History  of  the  Invertebrate  Animals  of  Kergue- 
lenslaud.     Prof.  Th.  Studer.     (3  plates.) 
Part  2  :— 

New  List  of  the  Animals  on  which  parasitic  Insects  live.  Gurlt,  with  additions 
by  Schilling. 

Helminthological  Contributions.     Prof.  Jos.  Uliany.     (1  plate.) 

New  Observations  on  Helniinthia.     Dr.  v.  Linstow.     (8  plates.) 

Short  Notices  on  some  new  Crustacea,  as  well  as  new  Localities  of  some 
already  described.     Prof.  Dr.  Kobby  Korsmann. 
Part  3  :— 

Attempt  at  a  Natural  Arrangement  of  the  Spiders,  with  Eemarks  on  indivi- 
dual Genera.     Dr.  Ph.  Bertkan.     (1  plate.) 

Reflections  on  the  Theory  by  which  the  Season-dimorphism  in  Butterflies  is 
explained.     Dr.  P.  Kramer. 

Contributions  to  the  Knowledge  of  the  Hermaphroditism  and  the  Spermato- 
phores  of  Gasteropoda.     Dr.  George  Pfeffer,     (1  plate.) 
Vol.  II.,  Part  4  :— 

Report  on  Researches  on  the  Natural  History  of  Mollusca  during  the  year 
1877.     Troschel. 

(Forty-fifth  year),  Vol.  I.,  Part  1  :— 

New  Acarida.     Dr.  P.  Kramer.     (2  plates.) 

Contributions  to  the  Knowledge  of  the  Lower  Animals  of  Kergnelensland. 
Prof.  Dr.  Studer.     (1  plate.) 

On  some  Turbellaria  of  the  White  Sea.     C.  Mereschkowsky.     (1  plate.) 

The  Fauna  of  Kerguelensland :  List  of  the  Species  hitherto  observed,  with 
short  notices  on  their  appearance  and  their  Zoo-geographical  relations.  Dr. 
Th.  Studer. 

BoTANiscHE  Zeitung,  Vol.  XXXVII.,  Nos.  1-5  (January): — 

On  Sprouting  in  the  Leaves  of  Isoetes.     K.  Goebel.     (4  woodcuts.) 

Observations  on  Entophytic  and  Entozootic  Plant-parasites.  P.  F.  Reinsch, 
(1  plate.) 

On  the  Movements  of  Oscillatoriese  and  Diatoms.     Th.  W.  Engelmann. 

Litteratur.  —  On  Discosporangiuni,  a  new  Genus  of  the  Phseos^DoreaB.  P. 
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Phycological  Studies:  Analyses  of  Marine  Algae.     Gustavo  Thuret. 

Researciies  on  the  Protein-Crystalloids  of  Plants.     A.  F.  W.  Schimper. 

Cryptogamic  Flora  of  Silesia,  Vol.  II.,  Part  1,  Algaj.     O.  Kirchner. 

Flora,  N.  S.,  Vol.  XXXVII.,  No.  1  (January)  :— 
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Flower  Leaves.     C.  Krans. 

Reply  by  H.  Bauke  to  Dr.  Prantl's  Article  on  the  Arrangement  of  the  Cells 

in  Flask-shaped  Prothallia  of  Ferns. 

Hedwigia,  Vol.  XVIII.,  No,  1  (January)  : — 
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Summary  of  the  Anthozoa  Alcyonaria   collected  during  the  Voyage  of  the 
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The  Crustacea  collected  by  W.  Peters  in  Mozambique.  Dr.  F.  Hilgendorf. 
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Austria. 

ArBEITEN  AUS  DEM  ZOOLOGISCHEM  INSTITUTE  DEE  UniVEESITAT 
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The  Crustacea,  Pycnogonida,  and  Tunicata  of  the  Austro-Hungarian  North 
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The  Goelenterata,  Echlnodermata,  and  Vermes  of  the  same  Expedition.  Dr. 
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(Vols.  XXXVI.  and  XXXVII.  were  issued  previous  to  1st  Jan., 

1878.) 

Vol.  XXXVIII.  :— 

Studies  on  the  Polypes  and  Mcdusse  of  the  Adriatic.  I.  Acalephse  (Disco- 
medusae).     Prof.  Dr.  C.  Cluus.     (11  plates.) 

Contributions  to  the  Investigation  of  the  Phylogeny  of  Plants.  Prof.  Dr.  C. 
V.  Ettingshausen.     (10  plates.) 

Annual  Period  of  the  Insect  Fauna  of  Austria-Hungary.  HI.  Hymenoptera. 
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The  Fossil  Miocene  Bryozoa  of  Austria  and  Hungary.  Part  III.  Dr.  A. 
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VOL.    II.  P 


210  BIBLIOGRAPHY. 

The  Central  Organ  of  the  Nervous  System  of  the  Selachii.  J.  V.  Rohon. 
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SiTZUNGSBERICHTE ViENNA    AcADEMY,    Vol.    LXVII.,    Parts    1-5, 

Section  111.,  Physiology,  Anatomy,  and  Theoretical  Medicine  (January 
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On  certain  Sensations  under  the  control  of  the  Optic  Nerves.  By  Ernst 
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On  the  Succession  of  Colours  in  Newton's  Rings.     By  A.  RoUett.    (4  plates.) 


Russia. 
Bulletin  de  la  Societe  Imp^riale  des  Natuealistes  de  Moscou, 
Vol.  Llll.  (1878),  No.  1  :— 

Attempt  at  a   new  Method  to  facilitate  the  Determination  of  the  Species 
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Lichenes  Finschiani.     Miiller  Arg. 
Lichenes  Fischeriani.     By  the  same  author. 
No.  2  :— 

Contributions  to  the  Fungus  Flora  of  Siberia.     II.     F.  von  Thiimen. 
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Memoires  de  l'Academie  Imperiale  des  Sciences  de  St.  Peters- 
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On  the  Morphology  of  the  Bacteria.     Prof.  L.  Cienkowski.     (2  plates.) 

Annulata  Semperiana.  Contributions  to  the  Knowledge  of  the  Annelida 
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Russian  Spiral  Foraminifera.  Prof.  Valerian  v.  Molkr.  (G  woodcuts  and 
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Vol.  XXVI.,  No.  1  :— 

The  Alga  Flora  of  the  White  Sea  and  the  adjacent  parts  of  the  Arctic  Ocean. 
Christoph  Gobi, 

Italy. 
Mittheilungen    aus    deb    Zoologischen    Station    zu   Neapel, 
Vol.  I.,  Parts  1-2  :— 

Observations  on  the  Mode  of  Life  of  some  Marine  Animals  in  tlie  Aquarium 
of  the  Zoological  Station.     R.  Schmidtlein. 

New  Researches  on  Pycnogonida3.     Ant.  Dohrn. 

Carcinological  Communications.     Paul  Mayer.     (2  plates  and  4  woodcuts.) 

On  Discospomngiuin,  a  new  Genus  of  Phffiosporese.     P.  Falkenberg.    (1  plate.) 

Halosphccra,  a  new  Genus  of  Green  Algae  from  the  Mediterranean  Sea. 
Dr.  Fr.  Schmitz.     (1  plate.) 

The  Segmental  Organs  of  the  Capitellida3.     Dr.  Hugo  Eisig.     (1  plate.) 

Comparative  Summary  of  the  Appearance  of  the  larger  Pelagic  Animals 
during  the  years  1875-1877.     R.  Schmidtlein. 

Reports  on  the  Zoological  Station  during  the  years  1876-1878.  Anton 
Dohru. 

The  Ctenophora  appearing  in  the  Gulf  of  Naples.    Dr.  Carl  Chun.    (1  plate.) 

The  Marine  Alga3  of  tlie  Gulf  of  Naples.     P.  Falkenberg. 

The  Lateral  and  Craterifoi-m  Organs  of  the  Capitellidaj.  Dr.  Hugo  Eisig. 
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Nuovo  Giornale  Botanico  Italiano,  Vol.  XI.  (1879),  No.  1, 
January : — 

Lichenes  Insulte  Sardinia).     F.  Baglietto.     (2  plates.) 
Bihliographj . —  News. 


(     210*     ) 


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**  These  pages  are  supplied  for  insertion  after  page  210,  with  the  view  of 
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*  Those  marked  (*)  do  not  contain  any  article,  &c.,  within  the  scope  of  the 
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LuDwiG,  H. — Morphological  Studies  on  Echinodermata.     Vol.  I.     23  plates 
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Balfoie,  F.  M.,  M.A.,  Y.U.^.—See  Eisig,  Dr.  H. 
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Mittheil.  Zool.  Stat.  Neapel,  I.,  Part  1. 
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Mittheil.  Zool.  Stat.  Neapel,  I.,  Part  2. 
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Quart.  Joum.  Micr.  Sci.,  XIX.,  p.  73. 
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10  pp.  Arb.  Zool.  List.  Univ.  Wien.,  I.,  Part  3. 

Hyatt,  J.  D. — Mechanism  by  which  Echinorhynchus  aucliors  his  Snout. 

Am.  Quart.  Micr.  Joum.,  I.,  No.  2. 
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Am.  Joum.  Micr.,  IV.,  No.  1. 

Leidy,   Prof. — Notice  of    a    Tetrarh>/nchus.      (From     '  Proc.    Acad.    Nat.  Sci. 

Philad.')  '  Ann.  ^  Mag.  Nat.  Hist,  III.,  No.  14. 

LoRENZ,    L. — On    the  Organization  of   the  Genera    Axine    and  Microcotyle. 

3  plates.  Arb.  Zool.  List.  Univ.  Wien.,  I.,  Part  3. 

Meqnin,  M.  p. — New  Observations  on  the  Development  and  Metamorphoses 

of  Tcenice.  Comptes  Pcndus,  LXXXVIIL,  No.  2. 


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*  Omitting  lists  and  descriptions  of  new  species,  local  fauna,  &c. 


2101f  BIBLIOGRAPHY. 

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holic Fermentation.] — Rei)ly  to  the  Notes  of  M.  Trccul  of  the  30th  December  and 
13th  January. — Observations  on  his  Reply, — Verbal  Observations  on  his  last 
Reply  and  Furtlier  Reply.  Comptes  Eendus,  LXXXVIII.,  Nos.  2,  3  &  6. 

„        „        Second,  Third,  and  Fourth  Replies  to  M.  Berthelot. 

Comptes  Eendus,  LXXXVIII.,  Nos.  2,  4,  &  6. 


BIBLIOGRAPHY.  2l0tt 

Planchon,  J.  E. — The  Polymorphism  of  Agaricus  melleus  Vahl. 

Comptes  JRendus,  LXXXVIII.,  No.  2. 
Plowright,  C.  B. — See  Cooke,  J.  C. 

QuELET,  Dr.  L.— The  Myxogastres.  Bev.  IfycoL,  I.,  No.  1. 

Reinsch,  P.  F. — See  Algse. 

RouMEGUERE,  C — Extraordinary  Case  of  Development  of  Bovista  gigantea  Nees, 
in  the  environs  of  Toulouse.  Rev.  MycoL,  I.,  No.  1. 

„  „      Origin  of  the  Genus  Microsphceria  Leveille. 

Eev.  MycoL,  I.,  No.  1. 
„  „      On  Telephora palmata  Fries.     Forma piradoxa  Nob. 

Eev.  MycoL,  I.,  No.  1. 
„  „     The  Preservation  of  Fungi  from  a  Scientific  point  of  view. 

Eev.  MycoL,  I.,  No.  1. 
„  „      See  Microscopy. 

ScHUTZENBERGER,  P.,  and  A.  Destrem. — Researches  on  Beer  Yeast. 

Conqytes  Eendus,  LXXXVIII.,  No.  6. 
„  „  „  On   the  Composition   of  Beer 

Yeast.  Comptes  Eendus,  LXXXVIII.,  No.  8. 

Seynes,  J.  DE. — On  the  Disease  of  the  Chestnut-trees. 

Comptes  Eendus,  LXXXVIII.,  No.  I. 
Thumen,  F.  de. — Fungi  Pomicoli— Monograph  of  the  Fungi  occurring  on  the 
Fruits  of  Temperate  Climates.     3  plates.     8vo.     Vienna,  1879. 
„  „  Fungorum  Novorum  Exoticorum  Decas. 

Eev.  MycoL,  I.,  No.  1. 
Tieghem,  p.  Van. — On  the  Fermentation  of  Cellulose. 

Gmptes  Eendus,  LXXXVIII.,  No.  5. 
Teecul,  a. — Reply  to  M.  Van  Tieghem  as  to  the  Origin  of  Amvlobacter. 

Co'iqjt'^s  Eend'is,  LXXXVIII.,  No.  9. 
„         „     Do  there  exist  among  the  lower  organisms  species  exclusively 
aerobian  and  others  anaerobian?  &c.  Comptes  Eendus,  LXXXVIII.,  No.  2. 

„         „     Reply,  last  Reply,  and  [further]  Reply  to  M.  Pasteur. 

Comptes  Eendus,  LXXXVIII.,  Nos.  3  &  6. 
Williams,  C.  F.  "W.  T. — See  Microscopy. 

Muscineae. 

Bescherelle,  Em. — Note  on  three  New  Species  of  Mosses  of  New  Caledonia, 
belonging  to  tlie  Genus  Pterohryella  C.  Miili. 

BuU.  Soc.  Bot.  France,  XXV.,  Part  1. 

Vascular  Cryptogams. 

Bauke,  H. — Reply  to  Dr.  Prantl's  Article  on  the  Arrangement  of  the  Cells  in 
Flask-shaped  ProthalUa  of  Ferns.  Flora,  XXXVII.,  No.  I. 

GoEBEL,  K. — On  Sprouting  in  tlie  Leaves  of  Isoetes.    4  figs. 

Bot.  Zat.,  XXXVII.,  No.  1. 

MICROSCOPY,  &c. 

Adan,  H.  p. — The  Invisible  World  Revealed.     Parts  1  to  8.    16  plates.     8vo. 
Brussels  and  Paris,  1879. 

American  Quarterly  Microscopical  Journal.  Am,  Nat.,  XIII.,  No.  3. 

Bedwell,  F.  a. — The  Oil-Immersion  ^  inch.  MidL  Nat.,  II.,  No.  13. 

Blackham,  Dr.  G.  E. — Angular  Aperture  of  Microscope  Objectives  (contd.). 
2  plates.  Journ.  de  Micr.,  III.,  Nos.  I  &  2. 

Brewster,  W. — On  Mounting  and  Preserving  the  Larvae  of  Butterflies  and 
Moths.  Sci.-Gossip,  No.  171. 

Browmng's  Compound  Achromatic  Microscope.     1  fig. 

M.  Journ.  Sci.,  I.,  No.  62. 
Certes,  a. — On  a  Method  of  Preserving  Infusoria. 

Comptes  Eendus,  LXXXVIII.,  No.  9. 
Chester,  H. — Artificial  Crystals  of  Gold  and  Silver.     5  figs. 

Am.  Journ.  Micr.,  IV.,  No.  1. 
Clark,  F.  C. — Removal  of  Air  from  Microscopic  Specimens. 

Am.  Nat.,  XIII.,  No.  1. 


210§§  BIBLIOGTlArHY. 

Clinch,  G.— A  new  Lamp  for  Microscopic  Mounting.         Sci.-Gossip,  No.  169. 
Cole  &  Son,  Cabinet  of  Microscopy  of.  Journ.  de  Micr.,  III.,  No.  2. 

Collins,  C,  Histological  Microscope  of,     1  fig.  „  „  „     No.  1. 

Cornet,  M. — The  Rivet  Microtome.  Bull.  Soc.  Belg.  Micr.,  V.,  No.  4. 

DiETZSCH,  O. — Tlie  mof^t  important  Foods  and  Drinks :  their  Impurities  and 
Adulterations.     3rd  Ed.     19  figs.     Svo.     Zuricli,  1879. 

Duval,  M. — On  the  Employment  of  Wet  Collodion  for  Microscopic  Sections. 

Journ.  Anat.  et  Fhijs.  (Bohin),  XV.)  No.  2, 
Fell,   G.   E. — Microscopic    Soire'es  —  An   Improved   Method   of  Exhibiting 
Objects.  Am.  Journ.  Micr.,  IV.,  No.  1. 

[Forrest,  H.  E.]— Apparatus  for  Drawing  Objects  under  the  Microscope. 

Midi.  Nat.,  II.,  No.  13. 
Hager,  Dr.  H. — The  Microscope  and  its  Employment.      6th  Ed.     231  figs. 
Svo.     Berlin,  1879. 

Henneguy,  F. — Method  of  Investigating  the  Embryos  of  Fishes.     (Trans',  from 
'  Bull.  Soc.  Philom.  Paris.')  Ann.  4'  Mag.  Nat.  Bist.,  III.,  No.  15. 

HiNCKS,  S.  C. — How  to  remove  Canada  Balsam  from  Slides. 

Sci.-Gossip,  No.  171. 
Hyde,  H.  C. — The  Microscope  in  Medical  Jurisprudence. 

Am.  Journ.  Micr.,  IV.,  No.  1. 
I.,  T.  E. — Hints  for  the  Young  Microscopist.     2  figs.  Sci.-Gossip,  No.  170, 

KiTTON,  F. — New  Forms  of  Camera  Lucida.     1  fig.     [Hofmann's,] 

Sci.-Gossip,  No.  171. 
Lankester,  Prof.  E.  R.— [Microscopical]  Eesearch  under  Difficulties. 

Nature,  XIX.,  No.  485. 

IMicroscopical  Library,  Sale  of  a.  Am.  Nat.,  XIII.,  No.  3. 

Morley,   E.   W.,   M.D.,    Ph.D. — On    the    Probable    Error    of    Micrometric 

Measurements.  -^>n.  Quar.  Micr.  Journ.,  I.,  No.  2. 

Mojsisovics,  Dr.  A. — Practical   Guide   for   Students   in   making   Zoological- 

Zootomical  Prt-parations.     110  figs.     8vo.     Leipzig,  1879. 

New  [American]  Microscopical  Societies.  Am.  Nut.,  XIIL,  No.  3. 

I'lessis,    G.   du. — Note   on   Preparing  and    Preserving    Delicate    Organisms. 
{Transl.)  Sci.-Gossip,  No.  171. 

Rogers,  Prof.  W.  A. — Limits  of  Accuracy  in  Measurements  with  the  Micro- 
scope. Am.  Nat.,  XIIL,  No.  1. 
„              „                Standard  Measures  of  Length. 

Am.  Quar.  Micr.  Journ.,  I.,  No.  2. 
EorMEGT.E!iE,  C— The  Microscopical  Study  and  Preparation  of  Fungi. 

Bcv.  Mi/coL,  L,  No.  1. 
Microscopical  Slides  of  Fungi  of  tlie  Eev.  J.  E.  Vize. 

Bcv.  Mycol.,  I.,  No.  1. 

Seiler,  Carl,  M.D.— Practical  Hints  in  Preparing  and  Mounting  Animal 

Tissues.     2  figs,     (fn part.)  Am.  Quar.  Micr.  Journ.,  I.,  No.  2. 

Smith,  A.— A  Live  Box.     2  figs.  *  Sci.-Gossip,  No.  170. 

„      „      A  Novel  Air-pump  for  removing  Air-bubbles  in  Slides.     1  fig. 

Sci.-Gossip,  No.  171. 
„      „      New  Form  of  Collecting-cane.     1  fig. 

Am.  Journ.  Micr.,  VI.,  No.  1. 
Smith,  J.  Edwards,  M.D.— [Beck's  Vertical  Illuminator] 

'  Am.  Nat.,  XIIL,  No.  2. 

Society  Screw.  „  „      No.  1. 

Spring  Clips  (Hawley's).  „  ,,      No.  3. 

Thin,  G. — See  Zoology  A. 

Tolles'  ^5  Objective.  Am-  Journ.  Micr.,  IV.,  No.  1. 

Watson  anu  Son,  Student's  Microscope  of.  Journ.  de  Micr.,  III.,  No.  2. 

Wilkins,   T.   S. — Microscopic   Pond  Life.     (Paper  read  before   the  "North 
Staffordshire  Naturalists'  Field  Club.")  Am.  Jovrn.  Micr.,  IV.,  No.  1. 

William."?.  C.  F.  W.  T.— On  Mounting  Micro-Fungi.     1  fig. 

Sci.-Gossip,  No.  169. 
Williams,  W.  Jf.— Spider's  Web  for  Micrometers.    (From  '  Journ.  Soc.  Arts.') 

M.  Journ.  Sci.,  I.,  No.  62. 
Zentmayer's  Reversible  Diatom  Stage.  „  „ 


(    211     ) 


PEOCEEDINGS  OF  THE  SOCIETY. 


A-NNUAL    Meeting  of  12th   Febeuary,  1879,   at   King's   College, 

Strand,  W.C. 

H.  J.  Slack,  Esq.,  President,  in  the  CLair. 

The  Minutes  of  the  meeting  of  8th  January  last  were  read  and 
confirmed,  and  were  signed  by  the  President. 


The  List  of  Donations  (exclusive  of  exchanges)  received  since  the 
last  meeting  was  submitted,  and  the  thanks  of  the  Society  given  to 
the  donors. 

From 

Brewer,  J.  A. — Flora  of  Surrey.     1863       Mr.  Crisp. 

Chester  Society  of  Natural  Science — Proceedings.     No.  2. 

1878 Mr.  Thos.  Shepheard. 

Drysdale,  J.,  M.D. — The   Germ   Theories  of  Infectious 

Diseases.     1878        The  Author. 

Hoggan,  G.  and  F.  E. — Etude  sur  les  Lympliatiques  de  la 

Peau.     (Extracted  from  the  'Journal  de  I'Anatomie 

and  de  la  Physiologie ') The  Authors. 

Koerber,    Dr.    G.    W. — Systema    Lichenum    Germanise. 

1855 Mr.  Crisp. 


The  President  read  his  Address  (see  p.  113). 

Dr.  Matthews  said  that  the  President,  at  the  commencement  of  his 
address,  had  stated  that  he  could  hardly  hope  to  rival  that  delivered 
at  their  previous  anniversary  by  Mr.  Sorby,  but  he  was  sure  that  all 
present  would  agree  that  they  could  not  have  had  laid  before  them 
more  interesting  and  important  matters  than  those  which  had  been 
dealt  with  that  evening,  and  he  had  great  pleasure  in  moving  that 
the  cordial  thanks  of  the  meeting  be  given  to  the  President  for  his 
address,  and  that  it  be  printed  and  circulated  in  the  usual  way. 

Dr.  W.  J.  Gray  having  seconded  the  motion, 

Dr.  Matthews  put  it  to  the  meeting,  and  declared  it  to  be  carried 
unanimously. 

The  President  then  read  a  copy  of  a  letter  which  he  had  addressed 
to  the  Council  as  to  his  reasons  for  not  offering  himself  for  re- 
election for  another  year,  which  was  followed  by  remarks  from  Mr. 
Crisj)  and  from  Dr.  Matthews  on  behalf  of  the  Council. 

Mr.  C.  Brooke,  F.K.S.,  then  took  the  chair. 


The  Report  of  the  Council  was  read  by  the  Junior  Secretary, 
Mr.  Crisp  (see  p.  216),  various  passages  being  received  with  demonstra- 
tions of  approval  from  the  meeting. 

Mr.  Glaisher,  F.R.S.,  said  he  rose  with  a  great  deal  of  pleasure  to 

p  2 


212  PROCEEDINGS    OP   THE    SOCIETY. 

move  tlio  adoption  of  the  report.  Having  long  been  connected  with 
the  Society,  and  having  always  taken  a  lively  interest  in  its  welfare, 
it  was  indeed  a  source  of  pleasure  to  him  to  find  that  it  now  had  a 
larger  annual  income  than  at  any  previous  time,  which,  couj^led  with 
the  fact  that  it  had  upwards  of  2100/.  to  the  credit  of  capital,  was  of 
itself  full  evidence  that  the  Society  was  prospering  and  flourishing. 

With  regard  to  the  Journal,  it  was  imposs'ble  for  him  to  look 
back  iijDon  the  past  without  recalling  how  the  late  Eev.  J.  B.  Eeade, 
Dr.  Bowerbank,  and  himself  had  always  worked  together  to  secxii-e  to 
the  Society  an  independent  Journal,  not  connected  in  any  way  with 
the  interests  of  trade.  They  had  that  now,  and  he  had  seen  the 
recent  numbers  with  the  greatest  satisfaction,  and  could  read  them 
again  and  again. 

When  he  had  the  honour  some  years  ago  of  filling  the  Presidential 
chair,  he  had  suggested  that  they  should  take  means  for  bringing 
kindred  societies  into  closer  connection  with  themselves.  His  idea 
then  was  that  the  Societies  should  pay  10s.  a  year,  or  some  such 
arrangement.  The  fact  that  a  proposition  was  to  be  brought  forward 
now  to  connect  these  kindred  societies  was  particularly  pleasing  to 
him.  Their  own  object  was  to  difii'use  and  encourage  microscopical 
study  and  inquiry,  and  there  were  many  excellent  workers  amongst 
the  provincial  societies  in  this  country,  whom  it  would  be  honourable 
to  the  Society  to  recognize.  It  was  therefore  with  very  much  more 
tha,n  usual  pleasure  that  he  moved  "  That  the  Eeport  be  received  and 
adopted,  and  that  it  be  printed  and  circulated  in  the  usual  way." 

Mr,  T.  Charters  White  had  much  pleasure  in  seconding  the  reso- 
lution whieli  had  been  so  warmly  spoken  to  by  Mr.  Glaisher,  and  he 
cordially  approved  of  the  j)roposal  in  regard  to  otlier  societies. 

The  Chairman  having  j)ut  the  motion,  declared  it  carried  unani- 
mously. 

Mr.  Crisp  then  moved  the  following  amendment  to  the  Bye-laws : — 

"  I.  The  1st  Bye-law  shall  read  as  follows  : — 

1.  The  Society  shall  consist  of  Fello-ws,  and  Ex-officio, 
Honorary,  and  Corresponding  Fellows  and  Associates. 

II.  The  following  Bye-law  shall  be  inserted  after  No.  15  a,  to  be 
numbered  No.  15  b  : — 

15  6.  The  Ex-officio  Fellows  shall  consist  of  the  Presidents 
for  the  time  being  of  such  Societies  at  home  or  abroad 
as  the  Council  may  from  time  to  time  recommend  and 
an  ordinary  or  annual  meeting  may  approve.  During 
their  term  of  office  they  shall  be  entitled  to  receive  the 
publications  of  the  Society  and  to  exercise  all  other 
privileges  of  Fellows  except  that  of  voting,  but  shall 
not  be  required  as  Ex-officio  Fellows  to  pay  any  entrance 
fee  or  annual  subscription." 

He  said  that  after  having  laid  his  proposition  as  to  Ex-officio 
Fellows  before  the  members  of  the  Council  and  obtained  their 
approval  of  it,  he  had  canvassed  the  matter  amongst  such  of  the 
Fellows  generally  as  he  had  been  able  to  meet  with  during  the  past 


PROCEEDINGS   OP    THE   SOCIETY. 


213 


two  months,  and  the  only  difficulty  that  he  had  exi^erienced  was  that  it 
was  too  uniformly  approved.  He  spoke  of  that  as  a  "difficulty"  because 
it  was  always  desirable  when  what  might  be  termed  radical  changes 
were  mooted,  that  both  sides  of  the  question  should  be  placed  before 
the  meeting,  which  was  thereby  enabled  to  come  to  a  sounder  decision. 
At  the  eleventh  hoiir,  however,  he  had  been  able  to  meet  with  a 
Fellow  who  entertained  some  objections. 

Mr.  J.  W.  Stephenson  having  seconded  the  motion, 
Mr.  Curties  said  that  his  objection  to  Mr.  Crisp's  proposal 
might  be  stated  in  a  word.  He  thought,  as  Mr.  Ghaisher  had  put  it, 
that  the  societies  should  pay  a  small  subscription,  as  it  was  intended 
that  they  should  receive  the  Journal  free  of  charge.  It  seemed  to 
him  that  if  they  were  to  be  giving  their  valuable  Journal  in  perpetuity 
in  this  way,  they  might  some  day  have  cause  to  be  sorry  for  it. 
Whether  this  liberality  was  justified  by  their  present  prosperity  ho 
would  not  venture  to  say,  but  it  should  be  remembered  that  at  the 
present  time  their  Honorary  Fellows  did  not  receive  the  Joiu-nal. 

A  further  discussion  ensued,  in  which  Mr.  T.  C.  White,  Mr. 
James  Smith,  Dr.  Braithwaite,  and  others  took  part,  after  which  the 
Chairman  put  the  motion  to  the  meeting  and  declared  it  to  be  carried 
unanimously. 

Mr.  Stephenson,  the  Treasurer,  presented  his  accounts  for  the 
year  1878  (see  p.  218). 

Dr.  Braithwaite  moved  that  the  accounts  be  received  and  adopted, 
and  printed  and  circulated  as  usual,  which  was  seconded  by  Mr. 
Glaisher,  and  carried  unanimously. 


The  List  of  Nominations  for  the  Council  was  then  read,  and  the 
Chairman  nominated  Mr.  A.  D.  Michael  and  Mr.  T.  C.  White 
Scrutineers. 

The  Scrutineers  having  handed  in  their  report  of  the  result  of  the 
ballot. 

The  Chairman  announced  that  the  following  Fellows  (being  those 
whose  names  appeared  in  the  list  of  nominations)  were  duly  elected  :— 

President—*  Lionel  S.  Beale,  Esq.,  M.B.,  F.E.S. 

Vice-Presidents — *  Robert  Braithwaite,  Esq.,  M.D. ;  Charles  T. 
Hudson,  Esq.,  M.A.,  LL.D.  ;  *  Henry  J.  Slack,  Esq.,  F.G.S. ;  and 
Henry  C.  Sorby,  Esq.,  F.E.S.,  Pres.  G.S. 

Treasurer — John  Ware  Stephenson,  Esq.,  F.R.A.S. 

Secretaries — Charles  Stewart,  Esq.,  M.K.C.S. ;  Frank  Crisp,  Esq., 
LL.B.,  B.A. 

Twelve  other  Members  of  Council — John  Badcock,  Esq. ;  William 
A.  Bevington,  Esq. ;  Charles  Jajues  Fox,  Esq. ;  *  James  Glaisher, 
Esq.,  F.R.S.,  F.R.A.S. ;  *A.  de  Souza  Guimaraens,  Esq. ;  William  J. 
Gray,  Esq.,  M.D. ;  *  John  E.  Ingpen,  Esq. ;  Emanuel  W.  Jones,  Esq., 
F.R.A.S. ;  *  William  T.  Loy,  Esq. ;  John  Matthews,  Esq.,  M.D. ; 
John  Millar,  Esq.,  L.R.C.P.E. ;  and  Thomas  Palmer,  Esq.,  B.Sc. 

*  Have  not  held  during  the  preceding  year  tlie  ofSce  for  which  they  were 
nominated. 


214  PK0CEEDING8   OF    THE   SOCIETY. 

Dr.  Lionel  S.  Beale,  M.B.,  F.R.S.,  was  then  called  upon  by  Mr. 
Brooke  to  take  the  chair  as  President  of  the  Society,  and  in  doing  so 
was  received  with  loud  and  long-continued  cheering.  He  said  that 
he  felt  deeply  indebted  to  the  Society  for  the  honour  which  they  had 
done  him  in  electing  him  their  President,  and  for  the  warmth  with 
which  he  had  been  received.  It  would  be  his  duty  as  well  as  his 
pleasure  to  come  amongst  them  as  often  as  possible,  and  as  he  had 
for  some  years  paid  comparatively  little  attention  to  the  Microscope, 
he  expected  to  learn  a  great  deal  by  attending  the  meetings. 


Mr.  Stephenson  said  he  had  received  from  Professor  Abbe  some 
photographs  of  Amphipleura  pellucida  and  Pleurosigma  angulatum, 
which  had  been  sent  to  him  by  Dr.  Woodward,  together  with  a  letter 
containing  Dr.  Woodward's  oj)inion  of  the  oil-immersion  objectives 
(part  of  the  letter  was  read,  see  p.  140,  and  the  photogi-aphs  were 
handed  round). 

A  Letter  was  read  from  Mr.  Badcock,  in  which  he  pointed  out  that 
in  the  report  of  the  meeting  of  11th  December  last,  he  was  made  to  say, 
in  reference  to  (Ecistcs  umhella,  "  at  which  time  he  showed  it  to  Mr. 
Oxley."  What  he  said  was  that  he  had  had  a  sketch  made  of  it  at 
the  time,  which  he  had  recently  shown  to  Mr.  Oxley. 


Mr.  Crisp  said  that  a  grave  charge  had  been  made  against  him, 
which  really  belonged  to  the  Society,  and  he  would  therefore  take  this 
opportunity  of  transferring  it  to  the  right  shoulders.  It  was  said 
that  when  a  large  and  complicated  form  of  Microscope  was  made,  it 
was  invariably  brought  to  the  Society  and  exhibited,  but  that  they 
never  exhibited  any  of  the  smaller  and  cheaper  forms  from  time  to 
time  produced — that  out  of  1000  microscopists,  however,  999  used  the 
latter  instruments,  and  only  the  one  man  in  the  1000  the  former,  so 
that  they  failed  somewhat  in  their  duty  in  not  giving  at  least  equal 
encouragement  to  what  it  was  contended  was  the  more  useful  instru- 
ment in  the  strict  sense  of  the  term.  He  must  say  (speaking  entirely 
for  himself)  that  he  thought  this  suggestion  was  not  without  force, 
and  by  way  of  doing  penance  for  his  own  shortcomings  he  had 
brought,  and  begged  to  present  to  the  Society,  three  of  the  recent 
smaller  instruments — the  "  Model "  of  Messrs.  Baker,  the  "  Binocular 
Economic  "  of  Messrs.  Beck,  and  the  "  Alpha  "  School  Microscope  of 
Mr.  Crouch. 

Mr.  Stephenson  said  that  if  Mr.  Crisj)  was  not  tired  of  receiving 
the  thanks  of  the  Society  he  should  like  to  move  a  vote  of  thanks  to 
him  for  his  valuable  presents. 

Dr.  Braithwaite  having  seconded  the  motion,  it  was  put  to  the 
meeting  and  carried  unanimously. 


PROCEEDINGS   OF    THE   SOCIETY.  215 

The  following  were  exMbited  :— 

Mr.  Baclcock  : — Three  lithographs  of  Infusoria  on  a  black  ground, 
illustrating  a  new  method. 

Mr.  T.  J.  Parker  : — Slides  of  Copepoda,  prepared  \ntb.  osmic  acid. 

Mr.  Stephenson  : — (1)  Five  forms  of  his  catoptric  immersion  illu- 
minator, viz. : — 

Three  of  1-inch,  ^-inch,  and  ^-inch  radius,  as  described  in  this 
Journal,  vol.  ii.  p.  36. 

A  cylindrical  illuminator  of  1-inch  radius  on  the  same  principle. 

A  fifth  consisting  of  two  lenses,  a  meniscus  and  plano-convex,  the 
curvature  of  the  latter  coinciding  with  the  curved  surface  of  the 
former,  so  that  the  achromatism  is  preserved  whilst  there  is  no  inter- 
ference with  the  power  of  total  reflection  at  the  surface  where  the 
film  of  air  between  the  lenses  intervened, 

(2)  The  following  photographs  taken  by  Dr.  Woodward  (lent  by 
Professor  Abbe) : — 

Amph'ipleura  pellucida,  in  balsam.  Zeiss'  ^^  '^^  immersion  (2630 
diameters). 

Same  valve.  Zeiss'  ^  oil  immersion,  with  Tolles's  amplifier 
(2500  diameters). 

Same  valve.  Powell  and  Lealand's  gV  ^ater  immersion  (2780 
diameters). 

Same  valve.  Powell  and  Lealand's  new  ^  water  immersion 
(2565  diameters). 

Same  valve.  Spencer's  -^  glycerine  immersion,  with  Tolles's 
amplifier  (2440  diameters). 

Pleurosigma  angulatum  (hexagons).  Zeiss'  ^^  oil  immersion  (2400 
diameters). 

Same  (difiraction  lines — Abbe's  experiment).  Zeiss'  \  oil  im- 
mersion (1700  diameters). 

Mr.  Ward: — (1)  Sections  (double  stained)  of  stem  of  Gulancha 
(Tinospora  cordifolia).  (2)  Sections  (double  stained)  of  stem  of 
Bhipsalis  Cassytha  (Cactacefe). 

Mr.  Crisp:— (1)  Baker's  "Model"  histological  Microscope. 
(2)  Beck's  small  binocular  Microscope  on  the  "  Economic  "  principle, 
with  American  glass  stage.  (3)  Crouch's  "Alpha"  school  Micro- 
scope, with  dividing  object-glass.  (4)  Professor  Mobius's  elaborate 
treatise  on  "  The  Structure  of  Eozoon  Canadense."  (5)  The  prepara- 
tions of  whole  insects  of  Herr  Petzold,  of  Vienna,  described  in 
'  Nature,'  vol.  xix.  (1879)  p.  301,  and  lent  by  the  editor. 


New  Fellows. — The  following  were  elected  Fellows  of  the 
Society,  viz. : — Messrs.  T.  Brown ;  L.  Dreyfus ;  C.  A.  Lucas ;  W.  M. 
Marshall  J.P. ;  and  T.  J.  Parker,  Assoc.  E.S.M. 


KEPOET  OF  THE  COUNCIL 

VHESENTEl)    TO 

THE   ANNUAL   MEETING. 


General  Position  of  the  Society. 
In  presenting  tlieir  Rei^ort  at  the  close  of  the  40th  year  of  the  Society's 
existence  the  Council  have  much  pleasure  in  congratulating  the  Fellows 
upon  its  continued  and  increasing  prosperity  and  vitality. 

The  number  of  Fellows  is  now  437.  Eleven  were  elected  during  the 
past  year  in  excess  of  the  number  elected  in  1877,  and  twelve  nominations 
for  Fellowship  have  been  received  since  the  beginning  of  this  year. 

Finances. 
The  Finances  of  the  Society  are  in  a  very  satisfactory  condition.  The 
Annual  Income  is  now  larger  than  at  any  j)revious  time ;  whilst  as  regards 
Capital,  the  funds  invested  in  Consols  and  India  Stock,  together  with  the 
Cash  in  hand,  amount  to  upwards  of  2100Z.,  as  will  be  seen  from  the 
Treasurer's  Accounts  presented  with  this  Eeport. 

New  Booms. 
The  Council  are   glad  to  be   able  to  announce  that   negotiations   are 
pending  with  the  authorities  of  King's  College,  by  which  it  is  anticipated 
that  the  Society  will  have  the  use  of  more  commodious  and  convenient  rooms. 

Library,  Instruments,  &c. 

The  Council  thought  it  prudent  to  limit  the  expenditure  during  the  past 
year  on  the  Library,  Instruments,  and  Apparatus,  on  account  of  the  difficulty 
that  existed  in  forming  any  reliable  estimate  of  the  probable  cost  of  tho 
Journal,  but  now  that  that  expenditure  has  been  ascertained,  and  having 
regard  to  the  amount  of  the  Society's  Capital,  they  see  no  reason  why  the 
full  siu'plus  of  Income  should  not  be  annually  expended  in  additions  to  the 
Library  and  Ai)paratus,  leaving  only  the  composition  fees  to  accumulate  in 
future  for  the  benefit  of  the  Capital  Account. 

Several  valuable  additions  have,  however,  been  made  to  the  Library 
during  the  past  year,  including  (from  Mr.  Crisp)  27  volumes  of  the  '  Annales 
des  Sciences  Natm-elles,'  10  volumes  of  the  'Zeitschrift  fiir  wissenschaftliche 
Zoologie,'  and  6  volumes  of  '  Grevillea,'  together  with  other  works.  The 
Council  have  also  accepted  from  the  same  Fellow  a  Cabinet  for  the  Instru- 
ments, &c.,  and  additions  have  been  made  to  the  Apparatus  and  Objects. 

A  detailed  and  very  complete  Catalogue  of  the  Instruments  and  Appa- 
ratus has  been  made  by  Mr.  Fox.  The  revision  of  the  Library  Catalogue, 
and  the  re-arrangement  of  the  Books  according  to  subjects  was  also  deter- 
mined upon,  but  these  matters  have  necessarily  been  postj^oned  in  conse- 
quence of  the  contemplated  change  of  rooms. 

Journal. 

The  Council  have  been  gratified  to  learn  that  the  new  series  of  the 
Journal  has  met  with  general  approval.  A  leading  feature  of  the  Journal 
(apart  from  the  Transactions  and  Proceedings  of  the  Society)  consists  of 
Notes  of  the  observations  and  investigations  of  interest  in  Biology  which 
are  recorded  in  the  Publications  of  the  principal  Academies  and  Learned 
Societies  throughout  the  world,  or  in  the  other  serial  publications  of  this 
and  other  countries. 

The  Council  find  that  this  plan  is  looked  upon  with  satisfaction,  not  only 
by  those  Fellows  who,  from  being  resident  in  the  provinces,  are  unable 


PROCEEDINGS    OE    THE    SOCIETY.  217 

to  obtain  access  to  mauy  of  tlie  works  througli  wbicli  sucli  obscrv..tious 
arc  scattered,  but  also  to  tbe  Fellows  and  Biologists  generally  in  Loudon, 
who,  apart  from  tbe  fact  of  tbe  original  communications  being  in  most 
cases  in  a  foreign  language,  are  assisted  in  tbeir  researches  by  having  the 
salient  points  of  recent  investigations  collected  together  in  a  condensed 
form. 

One  of  the  Secretaries  has  kindly  undertakeu  (as  an  honorary  office)  the 
Editorship  of  the  Journal. 

Business  at  the  Meetings. 

The  Council  are  of  opinion  that  it  would  be  useful,  in  the  best  sense  of 
the  term,  that  any  important  observations  in  Biology  made  by  Foreign 
Observers  should  be  noticed  at  the  Meetings,  and  with  this  view  they  have 
requested  the  Secretaries  to  bring  to  the  notice  of  the  Meetings  any  such 
observations,  illustrated  by  drawings  where  possible.  The  Council  will  bo 
glad  to  receive  the  co-operation  of  other  Fellows  in  carrying  out  this  object. 

The  Council  have  taken  into  consideration  the  necest>ity  of  making  some 
alteration  in  the  proceedings  at  the  Meetings,  so  as  to  avoid  tbeir  being 
protracted  to  the  late  hour  that  has  lately  been  rendered  necessary  by  the 
pressure  of  business  to  be  disposed  of,  and  they  think  that  a  sufficient 
remedy  will  be  found  in  providing  that  Papers  shall  not  be  read  in  cxtenso, 
except  in  special  cases.  They  hope  that  by  this  means  it  may  be  f(jund 
l)ossible  to  conclude  the  business  by  half-past  nine,  leaving  a  longer  period 
for  tea  and  coffee,  conversation  and  the  examination  of  the  objects  exhibited. 

Association  of  kindred  Societies. 

A  suggestion  has  been  made  to  the  Council  that  some  plan  should  bo 
devised  by  which  other  Societies  founded  for  kindred  objects  sliould  bo 
brought  into  association  with  this  Society.  It  would  not  of  course  be  possible 
to  provide  that  the  Members  of  other  Societies  should  ipso  facto  be  entitled 
to  the  privileges  of  Fellows,  but  the  Council  propose  that  the  Presidents  f<jr 
the  time  being  of  such  kindred  Societies  at  home  or  abrcjad  as  the  Council 
may  from  time  to  time  recommend,  and  the  Fellows  at  an  Ordinary  or 
Annual  Meeting  approve,  shall  be  ex-officio  Fellows,  being  entitled  to 
receive  the  '  Journal '  on  behalf  of  their  Societies,  and  to  exercise  all  other 
privileges  of  Fellows  except  voting.  The  Council  do  not  projjose  that  this 
should  be  limited  to  those  bodies  which  include  in  their  title  the  term 
"Microscopical"  (a  term  which,  as  applied  to  Societies  mainly  devoted  to 
Biological  and  Histological  investigations,  has  now  lost  most  of  its  original 
import),  but  should  include  all  whose  principal  object  is  Biological  liesearch 
in  any  of  its  branches. 

An  amendment  of  the  Bye-iaws  will  be  proposed  at  the  Meeting  to 
enable  this  to  be  carried  into  effect. 

Quelcett  Fund. 

The  Coimcil  have  turned  their  attention  to  the  disposal  of  the  Quekett 
Fund,  which  has  now  accumulated  at  interest  for  some  years  until  it 
amounts  (taking  the  cash  value)  to  upwards  of  180Z. 

The  Council  have  determined  to  recommend  to  the  Annual  Meeting  that 
a  sum  shall  be  aj^plied  in  the  purchase  of  books  (not  reducing  the  fund 
below  lOi/Z.),  the  balance  being  invested,  and  the  income  of  the  investments 
expended  annually  for  a  similar  purjiose,  the  books  to  bear  an  inscri2)tion 
indicating  the  source  from  which  they  were  purchased.  The  Council 
consider  that  in  this  way  the  Fund  will  be  applied  in  the  most  suitable 
manner,  as  regards  utility  to  the  Fellows  and  the  perpetuation  of  the 
niemorv  of  the  President,  in  whose  honour  it  was  formed. 


218 


PROCEEDINGS   OF    THE   SOCIETY, 


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proceedings  of  the  society.  219 

Meeting  of  12th  March,  1879,  at  King's  College,  Strand,  W.G. 
The  President,  Db.  Beale,  F.E.S.,  in  the  Chair. 

The  Minutes  of  the  meeting  of  12th  February  were  read  and  con- 
firmed, and  were  signed  by  the  President. 

The  President  said  that  the  amount  of  business  on  the  agenda 
that  evening  was  so  great  that  it  would  be  necessary  to  compress  the 
different  matters  as  much  as  possible,  or  they  would  not  be  able  to 
include  them  all.        

The  foUowiiig  Donations  (exclusive  of  exchanges)  received  since 
the  last  meeting  was  submitted,  and  the  thanks  of  the  Society  given 
to  the  donors  : — 

From 
Corden,  G. — The  Meteorology  of  Croydon.  1878.   The  Croydon  Mic.and  Nat.  Hist.  Club. 
Harting,  P. — Eecherehes  de  Morphologie  synthe'tique  siir  la 

production   artificielle  de  quelques   Formations  Calcaires 

Orgauiques.     1872 The  Author. 

Kabenliorst,     Dr.     L.  —  Deutschlaud's    Kryptogamen  -  Flora. 

1844-5         ' Mr.  Crisp. 

Siddall,  J.  D.,  and  H.  B.  Brady. — Catalogue  of  British  Recent 

Foraminifera,  for  the  use  of  Collectors.     1878 The  Authors. 

Four  slides  of  "Fossil  Diatoms"  from  Richmond,  Va.,  Peters- 
burg, Va.,  and  Nottingham,  M.D.  (U.S.),  were  presented  by  Mr.  C. 
L.  Peticolas,  through  Mr.  A.  Allen,  the  Secretary  of  the  Postal 
Microscopical  Society. 

Mr.  Crisp  mentioned  that  he  had  arranged  with  Mr.  Bolton  to  send 
him  a  supply  of  living  specimens,  which  he  would  bring  to  the  Wed- 
nesday evening  meetings,  and  would  be  glad  to  continue  the  arrange- 
ment if  it  were  found  that  the  Fellows  made  use  of  it- 


Lists  of  Nominations  under  the  new  Bye-law  relating  to   Ex- 
officio  Fellows  and  of  Honorary  Fellows  were  read  by  the  President. 


The  President  announced  the  completion  of  arrangements  with  the 
authorities  of  King's  College  for  the  occupation  by  the  Society  of  the 
room  in  the  south  corridor. 


Mr.  A.  D.  Michael  gave  an  abstract  of  his  paper,  "  A  Contribution 
to  the  Knowledge  of  British  OribatidsB,"  accomjianied  by  two  large 
coloured  drawings  and  four  slides. 

The  President  invited  observations  upon  Mr.  Michael's  paper, 
and  remarked  that  there  was  a  great  deal  of  interest  connected  with 
the  circumstance  he  mentioned  as  to  the  apparent  ability  of  these 
creatures  to  perceive  light  without  being  possessed  of  eyes.  There 
were  evidences  to  be  found  amongst  the  higher  animals  of  a  power 
of  receiving  impressions  of  light  without  the  aid  of  an  ophthalmic 
organ. 

Mr.  T.  J.  Parker  inquired  if  Mr.  Michael  had  found  out  anything 


220  PROCEEDINGS    OF    THE   SOCIETY. 

as  to  the  nature  of  the  white  i)owclcr  meutioned  as  being  found  upon 
one  species  of  the  mites  ? 

Mr.  Michael  said  that  he  had  little  doubt  as  to  the  use  of  this 
powder,  which  seemed  clearly  to  be  of  a  jn-otective  character.  Many 
other  species  not  provided  with  powder,  made  a  similar  protection  for 
themselves  by  rolling  in  the  mud.  As  to  its  origin,  he  was  unable  to 
say  anything  with  certainty,  but  thought  that  the  cast  skins  had  some- 
thing to  do  with  it. 

The  thanks  of  the  meeting  were  given  to  Mr.  Michael  for  his 
paper. 

Dr.  George  Hoggan  read  parts  of  a  paper  "  On  the  Development 
and  Retrogression  of  Fat-Cells,"  in  which  the  results  of  a  series  of 
observations  and  experiments  carried  out  by  himself  and  Mrs.  Hoggan 
were  minutely  detailed.  The  subject  was  well  illustrated  by  prepa- 
rations exhibited  under  twelve  Microscoj^es  in  the  room. 

The  President,  in  proposing  a  vote  of  thanks  (which  was  carried 
unanimously)  for  Dr.  Hoggan's  very  interesting  communication,  said 
that  so  many  paints  of  interest  had  been  referred  to  that  a  great 
deal  of  time  would  be  needed  to  discuss  it  thoroughly. 


Mr.  Beck  placed  upon  the  table  and  described  in  detail  a  new  large 
binocular  Microscope  which  he  had  devised  with  swinging  bar  for 
condenser,  mirror,  and  lamp,  and  with  improved  movements,  and 
invited  the  Fellows  to  criticise  it  freely  at  the  close  of  the  meeting, 
with  a  view  to  its  possible  further  improvement. 


Mr.  Crisp,  in  calling  attention  to  the  new  y^g^  oil-immersion  objec- 
tive of  1-26  numerical  aperture  (or  the  large  balsam  angle  of  114°  18')", 
said  that  they  had  a  very  interesting  communication  from  Professor 
Abbe  on  oil-immersion  objectives  in  general,  which  there  was  unfortu- 
nately no  time  to  read,  but  of  which  he  would  briefly  mention  the 
chief  points. 

In  the  first  place,  the  Society  would  be  pleased  to  find  that  Pro- 
fessor Abbe  had  given  full  credit  to  England,  and  to  this  Society  in 
particular,  in  regard  to  the  origination  of  these  objectives,  his  paper 
read  before  the  Jena  Society  being  entitled  "  On  Stephenson's  System 
of  Homogeneous  Immersion  for  Microscope  Objectives." 

Professor  Abbe  had  also  turned  his  attention  to  finding  aqueous  fluids 
fit  for  homogeneous  immersion,  and  believed  that  "  distilled  chloride  of 
zinc  dissolved  in  water  will  prove  to  be  an  excellent  substitute  for  tho 
oil  of  cedar  wood.  It  does  not  dissolve  balsam,  and  can  be  cleared 
off  by  water,  and  does  not  flow  like  the  cedar-oil ;  its  consistence  is 
like  thick  olive  oil."  Professor  Abbe  added  that  he  is  making  experi- 
ments with  other  preparations,  from  wliich  he  expects  good  results. 

A  third  point  related  to  a  suggestion  recently  made  by  Mr. 
Stephenson  that,  looking  to  the  large  working  distance  of  the  oil- 
immersion  system  and  the  optical  homogeaeity  of  crown  glass  and  the 
immersion  fluid,  the  front  lens  of  the  objectives,  instead  of  being  held 


PROCEEDINGS    OF   THE   SOCIETY.  221 

ill  place  by  tlie  brass  setting  (wliereby  necessarily  a  greater  or  less  part 
of  the  periphery  of  the  lens  was  rendered  ineffective),  should  be  fixed 
by  balsam  to  a  thin  plate  of  parallel  glass  rather  larger  than  the  lens, 
the  plate  itself  being  attached  by  its  jjeriphery  to  the  brass  mounting. 
Professor  Abbe,  in  reply,  said  that  he  had  last  summer  tried  the  plan 
with  perfect  success  in  some  experiments  made  to  test  its  efficiency, 
and  that  several  |ths  had  been  so  constructed.  The  device  necessarily 
introduced  a  very  delicate  additional  point  into  the  ojitical  system 
(the  balsam  film),  and  it  would  not  be  prudent  to  apply  it  where  it  is 
not  absolutely  necessary,  but  it  was  the  only  way,  in  his  opinion,  by 
which  an  objective  of  1  •  35  numerical  aperture  (  =  128^'^  balsam  angle) 
could  be  made,  and  he  hoped  before  long  to  accomplish  this. 

Mr.  Wenham  said  he  should  like  to  observe,  with  reference  to  the 
proposed  method  of  fixing  the  front  lens,  that  Mr.  Tolles  about  eight 
years  ago  constructed  an  objective  in  which  the  front  was  fixed  in  a 
similar  way. 

Mr.  J.  Mayall,  jun.,  said  that  he  had  examined  the  new  -^^  oil- 
immersion  belonging  to  Mr.  Crisp,  and  had  measured  the  aperture  with 
the  Abbe  apertometer.  He  found  it  slightly  less  than  the  figure  which 
had  been  mentioned.  As  to  flatness  of  field,  it  did  not  show  that  as 
he  should  have  expected  to  see  it  in  similar  powers  by  Powell  and 
Lealand  or  by  Tolles.  Whether  flatness  of  field  was  a  desirable 
quality  or  not,  he  would  not  engage  to  decide  ;  it  was,  at  any  rate,  a 
quality  much  sought  for  by  certain  opticians.  The  lens  was  specially 
designed  for  immersed  objects  or  for  objects  in  close  contact  with  the 
cover-glass,  and  when  used  on  such  objects  gave  fine  definition.  With 
an  immersion  illuminator  he  had  seen  the  striae  of  Amphlpleura  pelln- 
cida  in  balsam  by  lamplight  with  this  lens  more  easily  than  with  any 
other  he  had  examined. 


Mr.  T.  J.  Parker  read  a  paper  by  himself,  "  On  some  Applications 
of  Osmic  Acid  to  Microscopical  Purposes,"  illustrated  by  four  slides. 

The  President  said  that  the  Society  was  much  obliged  to  Mr.  Parker 
for  bringing  the  method  described  before  them,  as  it  appeared  from  the 
specimens  exhibited  to  be  a  very  excellent  one. 


Mr.  Crisp  said  that  some  little  misconception  seemed  to  exist  in 
America  as  to  the  discussion  at  the  October  meeting  on  a  unit  of 
micrometry.  At  the  end  of  that  discussion  Dr.  Edmunds  made  some 
remarks  on  the  Society's  standard  screw  for  objectives.  This  had 
apj)arently  been  supposed  to  refer  to  a  "  Whitworth  screw  carefully 
kept  in  the  custody  of  the  Society"  as  a  standard  for  micrometric 
measurements^  and  was  so  referred  to  in  an  article  by  Professor 
Rogers  in  the  January  number  of  the  '  American  Quarterly  Micro- 
scopical Journal.'  As  Professor  Rogers,  acting  on  this  assumption, 
proceeds  to  explain  that  "  an  absolutely  perfect  screw  cannot  be  taken 
as  a  standard,  and  hence  this  proposition  of  our  friends  abroad  is 
hardly  feasible  "  (for  reasons  which  we  must  all  readily  recognize),  it 
seemed  desirable  to  make  this  correction. 


222  PROCEEDINGS    OF    THE   SOCIETY. 

It  was  also  stated  by  Professor  Eogers  that  lie  had  a  large  collec- 
tion of  micrometers  by  diflferent  makers  at  home  and  abroad,  including 
transfers  from  every  well-known  j)rccision-screw  in  the  United  States  ; 
and  although  his  investigations  were  not  yet  quite  completed,  he  felt 
safe  in  saying  that  no  two  of  them  agree  at  a  given  temperature,  the 
errors  of  subdivision  being  in  many  cases  very  large,  and  in  all  cases 
easily  measurable. 

Mr.  Crisp  further  said  that  it  was  now  four  months  since  he  brought 
before  the  Society  the  resolutions  passed  at  the  Indianapolis  Congress 
of  American  Microscopists  in  August  last,  recommending  the  universal 
adoption  of  the  yi^  of  a  millimetre  as  the  unit  of  micrometry.  As 
apart  from  the  discussion  that  took  place  at  the  October  and  December 
meetings,*  the  subject  had  been  thoroughly  ventilated  in  the  interim, 
there  seemed  no  reason  for  postponing  the  subject  further,  and  there- 
fore with  the  view  of  bringing  the  matter  to  an  issue  one  way  or  the 
other,  he  would  give  notice  of  moving  the  following  resolution  at  the 
April  meeting :  — 

"  That  in  the  opinion  of  this  Society  the  most  convenient  unit  for 
micrometric  measurements  would  be  the  ^rno  ^^  ^  millimetre." 

He  had  purposely  abstained  from  framing  the  resolution  as  in 
any  way  a  recommendation  which  it  might  be  considered  they  had  no 
right  to  make,  leaving  it  to  express  simply  the  opinion  of  the  Society 
as  to  the  most  convenient  unit. 

In  supj)ort  of  the  first  point  embraced  by  the  resolution,  viz.  the 
selection  of  a  subdivision  of  the  metre  and  not  of  the  inch,  it  was 
hardly  necessary  to  remind  the  meeting  of  the  extent  to  which  the 
millimetre  was  used  at  the  present  time  in  the  scientific  world ;  whilst 
as  to  the  second  point,  the  adoption  of  the  yoVo  ^^  ^  millimetre  instead 
of  the  j}fQ,  it  would  be  borne  in  mind  that  the  former,  which  was  first 
suggested  in  Holland,  was  now  the  accepted  Continental  standard 
(under  the  name  of  micro-millimetre),  with  the  special  symbol  fx  (or 
sometimes  Mik.),  and  was  to  be  found  in  the  works  of  both  French 
and  German  writers  (particularly  diatomists),  and  in  the  Proceedings 
of  the  j)rincipal  Continental  learned  Societies.  Even  without  this  to 
recommend  it,  he  thought  there  could  be  little  or  no  difierence  of 
oj^inion  that  yIo  of  a  millimetre  was  far  too  large  a  standard. 

If  it  was  considered  desirable  for  any  purpose  not  to  lose  sight  of 
the  inch  altogether,  the  plan  suggested  by  Mr.  Beck  of  showing,  on 
one  micrometer,  subdivisions  both  of  an  inch  and  of  a  millimetre,  was 
a  very  convenient  one. 


Professor  Keith's  paper,  "  Note  on  Mr.  Wenham's  paper  '  On  the 
Measurement  of  the  Angle  of  Aperture  of  Objectives,' "  was  taken  as 
read  in  consequence  of  the  lateness  of  the  hour. 


Mr.  ToUes'  paper  on  "  An  Illuminating  Traverse  Lens  "  was  post- 
poned until  the  next  meeting. 


*  See  tliia  Journal,  vol.  i.  p.  310,  and  vol.  ii.  p.  108. 


PROCEEDINGS   OF   THE   SOCIETY.  223 

A  Note  by  Mr.  Crisp  "  On  the  Poison  Apparatus  and  Anal  Glands 
of  Ants  "  (illustrated  by  two  drawings)  was  taken  as  read  for  the  same 
reason. 

The  President  announced  that  after  the  conclusion  of  the  ordinary 
meeting  in  Ajiril  a  special  general  meeting  would  be  held  to  make  two 
alterations  in  the  Bye-laws.  First,  to  provide  that  the  'composition 
fee  payable  by  all  Fellows  hereafter  elected  should  be  31Z.  10s.  instead 
of  211. ;  and  secondly,  that  the  Presidents  or  Chairmen  of  the  Biolo- 
gical or  Microscopical  sections  of  Societies  coming  under  Bye-law 
15  &  might  be  elected  Ex-ofi&cio  Fellows  in  lieu  of  the  Presidents  of 
the  Societies. 

The  following  objects,  &c.,  were  exhibited:— 

Mr.  A.   D.   Michael : — Four   slides  illustrating  his  paper,   viz. : 

(I)  Tegeocranus  latus,  nymph  (newly  traced).  (2)  Tegeocranus  latns, 
perfect  creature.  (3)  Tegeocranus  lahyrinthicus,  nov.  sp.  (4)  Scuto- 
vertex  sculptus,  nov.  sp. 

Dr.  and  Mrs.  Hoggan : — Twelve  slides  illustrating  their  paper, 
consisting  of  preparations  from  (1  &  2)  the  broad  ligament  of  the 
uterus  in  a  pregnant  mouse ;  (3  &  4)  from  the  mesentery  of  a  rat ; 
(5  &  6)  from  the  mesentery  of  a  guinea-jng ;  (6)  from  the  skin  of  a 
leper  (subcutaneous  fat-layer) ;  (7)  from  the  mesentery  of  a  nursing 
mouse ;  (8  &  9)  from  the  mesentery  of  a  mouse  found  nearly  dead 
of  starvation  in  an  empty  jar ;  (10)  from  the  mesentery  of  a  rat ; 

(II)  from  the  mesentery  of  a  young  rat  weaned  a  week  previously  by  its 
mother,  which  had  brought  it  into  a  semi-starved  condition,  from  which 
it  had  recovered  ;  and  (12)  from  the  broad  ligament  of  the  liver  of  a  rat. 
All  illustrating  different  stages  of  development  and  retrogression  of  the 
fat-cell. 

[Preparations  were  variously  treated  : — (1),  (3),  (7),  (8),  (11),  and 
(12),  silver  and  pyrogallato  of  iron;  (2),  (4),  and  (10),  silver,  osmic 
acid,  and  logwood;  (5)  silver  and  logwood;  (6)  blood-vessels  injected 
first  with  silver,  then  with  carmine  gelatine,  and  section  afterwards 
treated  with  osmic  acid,  picro-carminate  of  ammonia,  and  indigo ; 
(9)  silver,  picro-carminate  of  ammonia,  and  osmic  acid. 

Mounted  (5)  in  varnish,  the  others  in  glycerin.] 

Mr.  Beck : — New  binocular  Microscope  with  swinging  bar  for 
condenser,  mirror,  and  lamp,  and  with  improved  movements. 

Mr.  Parker : — Five  slides  illustrating  his  paper,  viz.  :  (1)  Scyl- 
lai-us,  newly  hatched  Phyllosoma  larva.  (2)  Daphnia,  entire  and  dis- 
sected, showing  structure  of  heart.  (3)  Asellus,  mouth  parts  and 
abdominal  appendages.  (4)  Blatta,  salivary  gland  and  Malphi"-ian 
tubules.     (5)  Chara,  longitudinal  sections  of  terminal  bud. 

Mr.  J.  Mayall : — Tolles'  illuminating  traverse  lens. 

Mr.  Stephenson  :— New  -f^^  objective  (by  Zeiss)  on  the  homogeneous 
immersion  system  (shown  on  Podura). 

Mr.  Crisp  : — (1)  A  similar  objective.  (2)  Dr.  Seller's  mechanical 
microtome.  (3)  Two  forms  of  mounting  a  hemispherical  lens  for  im- 
mersion illumination  (by  Messrs.  Ross),  one  enabling  the  lens  to  be 


224  PROCEEDINGS    OF   THE    SOCIETY. 

approximated  more  or  less  to  tlio  slide.  (3)  The  Weber  slide  (see 
p.  55).  (4)  Small  form  of  Dr.  Woodward's  jirism  (see  vol.  i.  p.  246). 
(5)  Stephenson's  erecting  binocular,  with  improved  method  of  sub- 
stituting the  i^olarizing  plane  for  the  silvered  reflector  by  the  rotation 
of  a  screw,  also  with  removable  body  for  ready  conversion  into  a 
monocular,  rotating  binocular  body  for  the  u<e  of  two  observers, 
mirror  with  special  movements,  c^c.  (6)  The  first  parabolic  illumi- 
nator made  by  Mr.  Wenham  (in  1856.)  (7)  Slide  of  crystallized 
gold  (see  p.  193),  (lent  by  Messrs.  Beck). 


New  Fellows. — The  following  were  elected  Fellows  of  the  So- 
ciety : — The  Right  Hon.  Lord  Justice  Bramwell,  Messrs.  A.  M. 
Bremner,  T.  M.  Harvey,  T.  W.  Knight,  P.  Pochin,  G.  D.  Sawyer,  and 
E.  Woodall.  Honorary  Fellows. — Professors  P.  Harting,  of  Utrecht ; 
T.  Schwann,  of  Liege ;  and  Hamilton  L.  Smith,  of  Geneva,  N.Y.,  U.S. 

Walter  W.  Peeves, 

Assist.-Secrctary. 


^^,  11^:::^^ 


rTo  Non-Fellow 

Vol.  II.  No.  3.]  MAY,  1879.  [   Price  3s. 


;f^  rTo  Non-Fellows,^* 


Journal 


OF   THE 


Royal 
Microscopical  Society; 

CONTAINING   ITS 

TRANSACTIONS    AND    PROCEEDINGS, 

AND   OTHER   INFORMATION   AS   TO 

INVERTEBRATA  AND  CRYPTOGAMIA, 
EMBRYOLOGY,  HISTOLOGY,  MICROSCOPY,  &c. 

Edited^  tinder  the  direction  of  the  Publication  Committee^  by 

FRANK    CRISP,   LL.B.,   B.A.,   F.L.S., 

ONE  OF  THE  SECRETARIES   OF  THE   SOCIETY. 


WILLIAMS    &    NORGATE, 

LONDON  AND  EDINBURGH.  ^ii 


J 


r^- 


^^  J[t-» 


PRINTED  BY  WILLIAM  CLOWES   AND  SONS,]  [STAMFQKD  STREET   AND  CKARING  CROSS. 


JOURNAL 

OP   THE 

EOYAL  MICROSCOPICAL  SOCIETY. 

VOL.  II.    No.  3. 


CONTENTS. 

Tkansaotions  of  the  Society —  ^^^^ 
XII.  A  Contribution  to   the   Knowledge  of  British   Ori- 
BATIDJ5.     By  A.  D.  Michael,  F.E.M.S.,  with  the  assist- 
ance of  C.  F.  George,  M.R.C.S.E.  (of  Kirton  Lindsey) 

(Plates  IX.-XI.)  ..  225 

XIII.  Notes   on    the    Pygidia    and    Cerci    of    Insects.     By 

Henry  Davis,  P.E.M.S.  252 

XIV.  On  Stephenson's   System   of   Homogeneous   Immersion 

FOR  Microscope  Objectives.     By  Professor  E.  Abbe, 

of  Jena,  Hon.F.K.M.S .,  256 

XV.  The  Vertical  Illuminator  and  Homogeneous-Immersion 

Objectives.     By  J.  W.  Stephenson,  F.R.A.S.,  Treas. 

E.M.S 266 

XVI.  Note  on  Diagrams  (Plate  XII.)  exhibiting  the  Path 

OF  a  Eay  through  Tolles'  ^  Immersion  Objective. 

By  Professor  R.  Keith  ..  ..  ..  ..  ..  269 

XVII.  Note  on  Mr.  Wenham's  Paper  "  On  the  Measurement 

OF   THE    Angle   of   Aperture   of   Objectives."     By 

Professor  E.  Keith         ,.  ..  ..  ..  ..  270 

XVIII.  Eeply  to   THE   foregoing   Note.     By  F.  H.  Wenham, 

F.E.M.S.  271 

Notes  and  Memoranda  ..  ,.  ,,  ..  ..  ,.  272 

Nuclei  of  the  Blood-corpuscles  of  the  Triton 272 

Division  of  Curtilage  Cells         273 

Infitience  of  the  different  Colours  of  the  Spectrum  on  Animals       273 

Formation,  Fructification,  and  Division  of  the  Animal  Ovum 274 

Digestion  of  Albuminoids  by  Tnvertebrata       274 

Eozoon  Canadense      275 

Beticularian  Bhizopoda      276 

Protozoa  of  Northern  Bussia      276 

Deep-sea  Siphonophora      278 

Strange  Anomcdy  among  the  HydromedussB 278 

Muscle-epithelium  in  Anthozoa 279 

Phyloge7iy  of  the  Antipatharia 279 

Skeleton  of  the  Alcyonaria         , 279 

New  Species  of  Isis      281 

G or gonia  verrucosa 281 

Prehensive  Cells  in  the  Ctenophora 282 

Australian  Corals        282 

New  Genus  of  Milleporidse        283 

New  Genus  of  Starfishes 283 

Helminthology 283 

Excretory  Apparatus  of  Solenophorus  megalocephalus 284 

Anatomy  and  Embryogeny  of  tJie  Tseniadx     285 

Parasites  of  the  Lamellibranchiata 285 

New  Turbellarian        286 

Digestive  Organs  of  the  Fresh-water  Turhellarians        287 

Land  Planarians        ,      288 

Marine  Planarians 288 

Organization  and  Development  of  the  Oxyurtds 289 

Researches  on  Bonellia  viridis 290 

Development  of  Chxtopoda        291 


Notes  and  Memoranda — continued.  page 

Parasitism  of  Notommaia  on  Vaticheria . .      ..      • 291 

Kidney  of  the  Frcsh-icater  Crayfish 291 

Action  of  the  Heart  of  the  Crayfish . .      . .  292 

Natural  Classification  of  the  Spiders 293 

Researches  into  the  Developmental  Hidory  of  the  Spiders     294 

New  Genus  of  the  Cheliferidx 295 

Neto  Arari)ia        ..      ..      •.  295 

Organization  of  Myriapoda        295 

Polyxe7ius  lagurus,  De  Geer      296 

Parthenogenesis  in  Bees 297 

Spinning  Glands  of  the  Silkworm 297 

Odoriferous  Cells  in  Lepidoptera      298 

Seasonal  Dimorphism  of  Lepidoptera       298 

Development  of  Podurella 299 

Pespiratory  Organs  of  the  Larva  of  Culex       299 

SucMng  Plate  of  Dytiscus 300 

Development  of  Polyzoa      300 

Presence  of  a  Segmental  Organ  in  the  Endoproct  Polyzoa 301 

Power  of  Locomotioji  in  the  Tunicaia 302 

Extension  of  the  coiled  Amts  in  Rhy7ichonella 302 

Ene  of  the  Lamellihranchiata 303 

Foot  of  the  Unionidse          303 

"  Digger "  Mollusc  and  its  Parasites        303 

Hermaphroditism  in,  and   the    Spermatophores    of   the   Nephropneuslous 

Gasteropoda         304 

Mucous  Threads  of  Limax         304 

Development  of  the  Embryonal  Sac 305 

Piotein-cristalloids 306 

Composition  of  Chlorophiill        306 

Action  of  Light  and  Heat  on  Swarmspores  (Zoospores)         307 

Floating  Akfas  forming  Scum  on  the  Surface  of  Water 310 

Luminous  Bacteria  in  Meat       310 

Thuret  and  BorTiet'e  ^  Phycological  Studies' 311 

Relation  of  Lichens  to  Alga}  and  Fu7igi 311 

Influence  of  Light  on  Fungi      314 

Spores  on  the  upper  side  of  the  Pileiis  in  Hymenomycetes      314 

Change  of  Colour  in  tlie  Spores  of  Fungi         315 

Fungi  found  within  the  Shell  of  the  Egg          315 

Fungi  parasitic  on  the  Cabbage         315 

Fungus  Disease  in  Lettuces  {Peronospora  ganglitformis)      316 

Fungi  of  Stalactites 316 

Conidial  Fructifi^atiofi  of  Fumago 316 

Homology  of  the  ^^  Nucule"  of  Characeas         317 

Arrangement  of  the  CtUs  in  the  flat  Prothall'a  of  Ferns        317 

Apogamous  Ferns  and  the  Phenomenon  of  Apogamy  in  general           ..      . .  317 

Apogamy  in  Isoetes 319 

Microscopes  with  Swinging  Tailpiece        320 

^^  Penetration"  of  Wide-avghd  Objectives      322 

Process  for  Measaring  the  Solid  Angles  of  Microscopic  Crystals 323 

Method  of  Isohling  the  Connectioe-Tissue  Bundles  of  the  Skin 323 

: Process  for  Preparing  tlie  Embryos  of  Fishes          825 

Improvement  in  Aerating  Apxiuratus  of  Sea-water  Aquaria         ..'     ..      ..  326 

Further  Improvements  in  studying  the  Optical  Characters  of  Minerals      . .  326 

Imprr/ved  Achi  omatic  Condenser       328 

Seller's  Mechanical  Microtome 328 

Size  of  Histological  Preparations      329 

'■' Microscopy  "  and '^  Microscopical "  Societies        329 

Oil-Immersion  Objectives 331 

Method  of  Preserving  Infusoria,  &c 331 

Mixture  of  Oils  for  Homogeneous-Immersion  Objectives        332 

New  Fluids  for  Homogeneous  Immersion        332 

Standard  Micrometers         332 

Unit  of  Micrometry      332 

Obituary  ..           ..          ..          ..           ..          ,.          ,.          ..           ..  333 

Bibliography       ..           ..           ..           ..           ..           ,.           ,.           ,.  335 

Proceedings  of  the  Society    ..           ..           ,.           ..           ,.           .,  341 


HENRY  CROUCH'S 

FIEST- CLASS   MICEOSCOPES 

(JACKSON    MODEL), 

OBJECTIVES,  AND  ACCESSORIES. 


Catalogue,  fully  Illustrated,  on  Application. 


HENRY  CEOUOH,  66,  Barbican,  London,  E.G. 


Joaru.R  Mic.soc.voL.il j^i.ix. 


f  -L.       >T*    >-v     if'  »  t-  t-IT^  V 


Afi.cJi.a.«/.  cui-TuM^.oZe? 


Tfct.Jfciv-.TKxJT.fe  Co.lith . 


Te  g  e  o  cr  anu^  s  la^lJU-S 


JOUR.RMIC.SOC-VOL.ir.Pl.X. 


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y/esiyJ^^i^ym^^t^yt'  ZcCo.i^^-- 


ITctlax'-uLS  tkelep-roctTjLS.  1     6. 
Tegeocr^a.rLTJLs  elGiaga±:as,7"'"'0- 


JOUR.Pc.MIC.SOC.VOL.II.Pl.YI. 


A  Michael  a^-nca-.cUZ-. 


Tegeocraniis   coria-ceus,  1  . 
S CTj tov-eT>tex  sculp tus  4h  ~  3 


Westlfewyruxnic  Co  iMh.. 


JOURNAL 

OF    THE 

ROYAL  MICROSCOPICAL  SOCIETY. 

MAY,  1879. 


TRANSACTIONS  OF  THE   SOCIETY. 


XII. — A  Contribution  to  the  hnoivledge  of  British  OrihafidcV. 

By  A.  D.  Michael,  F.E.M.S.,  with  the  assistance  of  C.  F.  George, 
M.E.C.S.E.  (of  Kirton  Lindsey). 

(Read  hefore  the  Society,  March  12th,  1879.) 

Plates  IX.,  X.,  and  XI. 

Amongst  the  Acarina  are  various  groups  which  have  received 
little  attention  in  England,  but,  probably,  there  is  not  any  family 
that  has  met  with  more  neglect  than  the  Orihatidie,  or  beetle 
mites. 

The  common  Damseus  genicidatus  is  well  known,  and  is 
mentioned  by  Curtis,*  who  discusses  whether  it  is  injurious  to 
vegetation.  I  have  seen  a  print,  cut  from  some  work  published  in 
1800,  inappropriately  called  the  "  Wandering  mite,"  which  is 
evidently  one  of  the  Oribatidse,  probably  a  Notaspis.  Johnston  t 
mentions  a  Carabodes  nitens  in  Berwickshire,  but  I  doubt  it  being 
possible  to  identify  it,  although  it  is  evidently  one  of  the  Oribatidae ; 


DESCRIPTION  OF  PLATES. 
Plate  IX. 

Fig.  1. — Tegeocranus  latus.     Larva. 

„     2. —  „  „         Nymph    full    grown.     The  central   ellipse  on  the 

back  is  the  cast  dorsal  skin  of  the  larva,  the  two 
next  rings  are  the  similar  cast  skins  of  the  nymph 
in  its  earlier  stages,  a,  stigmatic  hair  seen  side- 
ways ;  5,  the  other  similar  hair  seen  edgeways. 

„    3, —  „  „         Mature  (perfect)  creature  x  65.     «,  wing-like  ex- 

pansions of  the  cephalothorax  ;  h,  stigmatic  hairs  ; 
c,  projection  of  the  sternal  plate  cleft  for  the  inser- 
tion of  the  first  pair  of  legs ;  d,  projecting  lateral 
ridge  (at  a  lower  level  than  the  dorsal  plate), 
forming  a  protection  to  the  first  and  second  pairs 
of  legs  when  they  are  folded  up. 

„     4. —  „  „         Palpus  (copied  from  Nicolet). 

„     5, —  „  „        Mandible  „  „ 


*  '  Farm  Insects.' 

t  'Hist.  Berwickshire  Nat.  Field  Club,'  vol.  iii.  p.  113. 
VOL.    II.  Q^ 


226  Transactions  of  the  Society. 

some  parts  of  his  description  must  be  errors,  while  other  necessary 
particulars  are  omitted. 

The  occurrence  of  some  Hoplophora  has  been  noticed  by- 
Mr.  George,  *  and  there  may  be  other  flying  notices.  I  am  not 
aware  that  anyone  has  attempted  to  search  out  and  put  on  record 
the  species  found  in  this  country.  The  late  Andrew  Murray  f 
simply  notices  one  species  in  each  of  Nicolet's  genera,  remarking 
that  many  of  them  might  probably  be  found  here  if  properly 
looked  for. 

This  neglect  cannot  arise  from  lack  of  objects  of  interest, 
as  anyone  paying  attention  to  them  will  soon  ascertain.  I  com- 
menced collecting  and  investigating  them  last  spring ;  while  so 
engaged   I  accidentally  ascertained   that   Mr.  C.  F.  George,   of 

Plate  X. 
Fig.  1. — Nothrus  theleproctus.     Egg. 

„    2. —      „  „  Larva. 

„    3. —      „  „  Mature  creature  x  65.     a,  east  dorsal  skin  of  larva ; 

b,  ditto  of  nymph  (first  change)  ;  c,  ditto  of  ditto 
(second  change) ;  d,  ditto  of  ditto  (third  change) ; 
e,  back  of  perfect  creature ;  /,  stigmatic  hair  ; 
q,  stigmata. 

„    4.—      „  „  Palpus  X  300. 

„     5.—      „  „  Mandible  x  300. 

„     6.—      „  „  Maxilla  x  300. 

„  7. — Tegeocranus  elongatus.  a,  hairs  of  the  verlex ;  b,  hairs  proceeding  from  edge 
of  wing-like  expansion  of  cephalothorax  and  cross- 
ing in  front  of  the  rostrum. 

„     8. —  „  „         Under  side.     «,  labium ;   b,  wing-like  expansion  of 

cephalothorax ;  c,  shorter  ditto  lower  in  level ; 
d,  projection  of  sternal  plate  indented  for  insertion 
of  first  and  second  pairs  of  legs ;  e,  anal  plates ; 
/,  genital  plates. 

„    9.  -  „  „        Palpus  X  300. 

„  10.—  „  „        Mandible  x  300. 

Plate  XL 
Fig.  1. —  Tegeocranus  coriaceus  X  65. 

„     2. —  Tegeocranus  labyrinthicus  X  65. 

^^    3. —         jj  „    Mouth  organs,    a,  labium  ;  b,  mandible  partly  show- 

ing from  below  the  maxilla ;  c,  maxilla ;  d,  palpus. 

„  4. — Scutovcrtex  sculptus  X  65.  a,  tectum ;  6,  wing  of  ditto  ;  c,  terminal  hair 
of  same  wing;  d,  projecting  point  of  dorsal  plate; 
behind  is  seen  the  clearer  depressed  area  arising 
from  the  absence  or  thinness  of  the  chitine;  e,  stig- 
matic hair ;  /,  projection  from  sternal  plate  be- 
tween third  and  fourth  pairs  of  legs. 

„     5. —         „  „       Under   side  x  C5.     a,   rtflexed   edge  of  the  dorsal 

plate  seen  embracing  the  sternal  plate. 

„    6. —        „  „       Fourth  and  fifth  joints  and  tarsus  of  first  pair  of  legs, 

showing  projection  of  fourth  joint  X  300. 

„    7.—        „  „       Palpus  X  300. 

„     8.—        „  „       Mandible  x  300. 

,,     9. —        „  „       End  of  a  maxilla. 


*  '  Science-Gossip,'  1877,  p.  205. 
t  '  Economic  Entomology.' 


British  Orihatidse.     By  A.  D.  Michael.  227 

Kirton  Lindsey,  was  doing  the  same  thing.  I  communicated  to 
him  that  I  was  preparing  a  paper  on  the  subject  to  be  submitted  to 
this  Society,  and  he  at  once  placed  his  observations  and  specimens 
at  my  disposal,  a  piece  of  generosity  which  I  desire  most  gratefully 
to  acknowledge.  I  have  endeavoured  to  mention  his  observations 
as  they  occur.  My  searches  have  been  made  during  the  past 
twelve  months,  near  Tam worth,  in  Warwickshire ;  at  Wandsworth, 
in  Surrey ;  Epping  Forest ;  and  the  shores  of  Loch  Maree  and 
Loch  Ewe,  in  the  Eoss-shire  Highlands ;  Epping  being  more 
thoroughly  hunted  than  the  other  places. 

Mr.  George  has  collected  entirely  at  Kirton  Lindsey,  in 
Lincolnshire. 

I  am  aware  that  the  '  Transactions '  of  this  Society  are  not  the 
place  to  monograph  a  family  of  British  Arachnida,  although  of 
microscopic  size,  nor  would  the  number  of  plates  which  can  fairly 
accompany  a  paper  like  this  enable  one  to  do  so,  even  if  twelve 
months'  searching  were  sufficient  for  the  purpose,  which  is  far  from 
being  the  case ;  but  I  have  thought  that  our  observations  might 
possibly  be  of  sufficient  interest,  and  would  contain  sufficient 
entirely  new  matter,  to  excuse  my  occupying  a  little  of  your  time. 

The  plan  I  have  followed  is  to  give  first  a  short  summary  of 
the  principal  distinctive  characters  of  the  family  and  a  reference  to 
the  leading  foreign  bibliography  (there  is  not  any  English)  ;  then 
such  observations  as  to  general  matters  as  I  have  to  submit ;  and, 
finally,  to  give  a  list  of  the  species  found,  with  any  observations  as 
to  each  species  which  I  have  thought  new  and  interesting,  and  also 
details  of  such  larvae  and  nymphs,  which  had  not  been  before 
observed,  as  I  have  been  able  to  rear,  so  as  to  be  certain  what 
species  they  belonged  to. 

Distinctive  Characters  of  the  Family. 

Taking  for  granted  the  distinctions  common  to  all  Acarina,  the 
Oribatidte  are  formed  into  a  strongly  marked  group  by  the 
following  characters,  viz. : — 

1.  A  hard  chitinous  exo'skeleton,  as  in  a  beetle ;  it  is  this 
resemblance  that  has  given  origin  to  the  name  of  beetle  mites. 
The  chitine  covers  every  external  part  of  the  j)erfect  creature,  and 
is  very  hard,  but  extremely  brittle  and  entirely  devoid  of  elasticity, 
so  that  on  any  pressure  it  breaks  into  fragments ;  it  is  always  black 
or  brown. 

2.  The  form  of  the  stigmatic  and  tracheal  system,  which  is 
peculiar,  consisting  of  two  hard,  more  or  less  projecting,  stigmata, 
of  a  short  tubular  or  trumpet  shape,  one  at  each  side  of  the 
cephalothorax  near  the  juncture  with  the  abdomen  (but  varying  a 
little  in  position) ;  below  each  of  the  stigmata  is  an  air  sac,  and 
some  long  filiform  tracheae  supplying  the  body,  and  from  inside 

Q  2 


228  Transactions  of  the  Society. 

the  edge  of  each  of  the  stigmata  always  proceeds  a  hair,  the  shape 
of  which  varies  with  the  species ;  it  is  known  as  the  protecting  hair, 
and  I  have  a  few  words  to  say  about  it  hereafter, 

3.  The  legs  have  invariably  five  joints,  and  are  terminated  by 
either  one  or  three  claws,  without  sucker  or  caroncle. 

4.  The  palpi  have  five  joints. 

5.  The  ventral  surface  is  pierced  by  three  openings,  the  first 
formed  anteriorly  by  the  overhanging  of  the  dorsal  surface  and 
posteriorly  by  a  deep  indentation  of  the  sternal  plate ;  through 
this  opening  the  palpi  and  organs  of  the  mouth  are  protruded  (or 
withdrawn  at  will),  and  in  most  species  the  orifice  can  be  almost 
entirely  closed  by  the  labium.  The  second  orifice  is  rhomboidal 
or  oval,  and  is  always  closed  by  two  chitinous  plates  like  folding 
doors,  which  open  to  afibrd  a  passage  to  the  reproductive  organs. 
The  third  orifice  is  the  anal,  and  is  similar  in  shape  to  the  genital, 
and  is  closed  by  similar  plates,  which  are  usually  larger  than  the 
genital  ones. 

6.  There  never  are  any  visible  eyes. 

Bihliograpluj. 

I  have  not  attempted  to  give  an  exhaustive  bibliography,  but 
only  referred  to  the  few  authors  whose  works  are  of  importance, 
and  a  reference  to  which  is  almost  necessary  for  the  latter  part  of 
this  paper ;  these  I  have  arranged,  not  in  order  of  date,  but,  to  some 
extent,  in  order  of  importance. 

The  first  place  must  be  assigned  to  Nicolet's  monograph  of  the 
Oribatidae  in  the  neighbourhood  of  Paris,*  an  admirable  work, 
beautifully  illustrated,  clear,  and  distinct.  I  have  followed  his 
arrangement,  introducing  such  species  as  Nicolet  did  not  find,  in 
what  appear  to  me  to  be  their  respective  proper  places ;  but,  while 
doing  so,  I  may  say  that  I  probably  might  not  quite  adhere  to  this 
system  were  I  myself  writing  a  monograph,  as,  although  it  has 
the  advantage  of  great  distinctness,  it  seems  to  me  highly  artificial, 
and  I  doubt  if  one  or  two  of  the  distinctions  can  be  supported,  for 
instance,  the  great  stress  laid  on  the  difference  between  homodactyl 
and  heterodactyl  claws ;  I  doubt  whether  any  truly  homodactyl 
claws  exist  in  the  family,  it  seems  to  me  probably  more  a  question 
of  degree. 

C.  L.  Koch,  in  his  great  work,  f  has  described  and  figured  an 
immense  number  of  species  and  given  their  classification  in  a  sub- 
sequent work ;  %  these  two  books  form  a  vast  storehouse  of  know- 
ledge relative  to  the  Acarina,  and  a  monument  of  human  industry  ; 
they  are  an  absolute  necessity  to  the  apterologist,  but  it  must  be 

*  '  Archives  du  Museum,'  1855,  t.  7. 

t  '  Deutscbland's  Crustaceen,'  &c. 

j  '  Uebersicht  des  Arachuidensystems.' 


British  Oribatidse.     Bjf  A.  D.  Michael  229 

confessed  that  the  descriptions  and  figures  are  often  scarcely  suffi- 
cient for  identification,  and  that  every  specimen  which  presents  the 
smallest  difference  is  given  as  a  distinct  species ;  often  the  male, 
female,  and  nymph,  and  even  the  nymph  after  each  change  of  skin, 
are  given  as  distinct  species,  producing  confusion.  Koch  had 
scarcely  a  genius  for  classification ;  his  genus  Nothrus  for  instance 
is  a  strange  collection  of  heterogeneous  creatures.  I  should  think 
it  my  fault  that  several  of  his  genera  do  not  convey  any  clear  idea 
to  my  mind,  if  such  men  as  Nicolet,  Mui'ray,  and  Megnin,  had  not 
said  the  same  thing  before  me. 

Hermann*  has  described  and  figured  several  species  in  a 
manner,  like  all  his  work,  most  admirable,  considering  the  date,  but 
not  always  sufficient  for  modern  requirements. 

Duges,  t  in  his  excellent  papers  on  the  Acarina,  treats  of  the 
Oribatidge,  but  more  shortly  than  of  the  other  families. 

Ed.  Claparede  t  gives  some  highly  interesting  observations  of 
the  transformations  of  Hoplo-pliora,  &c. 

There  are  numerous  other  authors,  such  as  Gervais,§  De 
Geer,  ||  Latreille,  1[  Lucas,**  Thorell,tt  &c.,  whose  works  contain 
valuable  information. 

General  Olservations. 

It  appears  to  be  the  result  of  modern  research  that  the 
Orihatldai  are  the  only  family  of  Acarina  no  species  of  which  is 
ever  parasitic  at  any  stage  of  its  existence ;  the  various  Sarcoptidfe 
and  some  others  of  the  true  Acari  are  always  parasitic,  the 
Ixodidw  partly  so ;  the  Gamasinse  and  many  of  the  Hydrachnidai 
are  parasitic  during  the  nymph  stage ;  the  Tromhididm  during  the 
curious  hypopial  nymph  stage ;  XX  and  ]\legnin  has  lately  shown 
that  even  some  of  the  Cheyleti  are  in  a  sense  parasitic,  §§  but 
it  never  occurs  amongst  the  Orihatidw. 

It  seems  to  me  that  the  numerous  contrivances  for  protecting 
the  legs  in  the  Oribatidse  have  not  been  sufficiently  noticed,  nor 
their  purpose  understood  ;  the  animals  are  all  vegetable  feeders,  and 
are  slow  and  cannot  escape  from  enemies  by  running  ;  they  are  not 
provided  with  weapons  of  defence,  but  are  furnished  with  a  very 
hard  shell,  and  their  safety  consists  in  trusting  to  it  and  "  shamming 
dead  " :  this  would  be  useless  if  their  legs  were  exposed.  Everyone 
who  has  seen  a  predatory  mite  seize  a  victim,  knows  that  it  usually 

*  '  Me'moire  Apterologiqiie,'  Strasbourg,  1804. 

t  '  Annales  des  Sciences  Natiu-elles,'  lS3-i. 

X  '  Studien  iiber  die  Acariden,'  Leipzig,  1868. 

§  'Histoire  Nat.  des  Apteres,'  Paris,  1847. 

II  'Me'moires  pour  servir  a  I'Hist.  Nat.  des  Insectes,'  Stockholm,  1778. 

^  '  Hist.  Nat.  des  Crustaces  et  des  Insectes,'  Paris,  An  XII. 

**  '  Exploration  Scientifique  de  I'Alge'rie.' 

tt  '  Oefv.  Sv.  Ak.,'  28,  695.     (1871.) 

XX  Megnin,  'Journal  de  rAuatomie,'  1874. 

§§  Ibid.,  1878. 


230  Transactions  of  the  Society. 

does  so  by  the  leg,  and  although  a  cheyletus  might  not  be  able  to 
make  much  impression  on  one  of  the  Oribatidse,  yet  a  chelifer  would 
probably  be  more  successful.  This  protection  of  the  legs  is  carried 
to  its  highest  perfection  in  Hoplojohora,  where  the  legs  are  short  and 
project  on  the  ventral  surface  near  the  hinder  part  of  the  cephalo- 
thorax,  which  is  only  united  to  the  abdomen  by  an  articulation 
allowing  the  former  to  shut  down  on  the  ventral  surface  of  the 
latter,  the  hood  which  covers  the  cephalothorax  forming  a  hard, 
close,  box  over  the  legs  (which  have  been  retracted),  and  the 
various  parts  of  the  mouth  &c.,  so  that  (the  genital  and  anal  plates 
being  closed)  one  unbroken,  hard  surface  is  presented  to  the 
enemy,  and  it  is  amusing  to  watch  the  cephalotliorax  being  raised 
and  the  legs  cautiously  making  their  appearance  when  the  danger 
is  supposed  to  be  over. 

In  the  genera  Pelops  and  Orihata  there  is  a  chitinous  flexible 
wing-like  expansion  to  the  fore  part  of  the  edge  of  the  abdomen, 
projecting  a  little  forward ;  when  any  alarm  occurs,  the  legs  are 
neatly  folded  against  the  body  and  this  wing-like  cover  closed  over 
them,  making  the  whole  as  snug  and  as  slippery  as  possible. 

In  the  genera  Tegeocranus,  Notasjns,  &c.,  the  sternal  plate  or 
the  lower  edge  of  the  dorsal  bears  several  strong  projecting  ridges, 
leaving  deep  depressions  between  them  into  which  the  legs,  when 
folded  up,  exactly  fit ;  the  leg  generally  being  bent  at  the  middle 
joint,  and  one  ridge  lying  within  the  flexure,  so  that  the  whole  leg 
can  lie  upon  the  under  surface  of  the  body,  and  be  almost  as  well 
protected  as  by  the  former  methods. 

In  Eremseus,  &c.,  the  coxse  of  the  first  and  second  pairs  of  legs 
are  set  in  deep  indentations  of  the  sternal  plate  open  above  and 
below  with  strong  projections  between.  I  have  observed  that  this 
arrangement  not  only  protects  the  leg,  but  also  enables  the  creature 
to  raise  it  right  over  its  back,  which  is  useful  to  it,  enabling  it  to 
right  itsylf  when  it  falls  on  its  back,  as  it  frequently  does. 

While  treating  of  the  modes  in  which  Orihatid/B  protect  them- 
selves, I  may  call  attention  to  the  singular  habit  which  several 
species,  and  the  nymphs  of  others,  have,  of  coating  themselves  with 
extraneous  matter;  this  is  attained  in  various  ways.  In  most 
members  of  the  genus  Nothrus  the  back  is  concave,  and  dirt  is 
piled  in  the  concavity  ;  in  Damasus  genicuJatus  and  D.  clavipes,  the 
back,  particularly  in  the  nymphs,  is  provided  with  numerous  long 
hairs ;  it  is  by  some  means  plastered  witli  mud,  which  adheres  to  the 
hairs,  and  indeed,  it  is  not  easy  to  get  it  ofi"  without  destroying  the 
creature.  In  Damseus  pajnllipes  and  D.  vertieiUipes  a  difierent 
mode  is  seen ;  the  whole  creature,  including  legs,  and  often  each 
individual  hair,  is  thickly  coated  with  white  dust,  so  that  the  animal 
looks  as  if  it  had  been  rolled  in  plaster  of  Paris. 

Another  strange  habit  of  many  of  the  Oribatidfe,  which  also  is 
probably  protective,  consists  in  carrying  on  the  back  a  pile,  or 


British  Orihatidse.     By  A.  D.  Michael.  231 

shield,  of  the  dorsal  parts  of  the  cast  skins  from  the  earlier  stages, 
which,  adhering  closely  to  the  back  of  the  perfect  creature,  or  the 
nymphs,  as  the  case  may  be,  give  it  the  appearance  of  being  a 
totally  different  shape  from  what  it  is;  this  is  seen  in  Damseus 
verticilUpes,  Nothrus  thelej^roctus,  and  others,  and  is  admirably 
shown  in  the  nymph  of  Tegeocranus  latus. 

Before  closing  these  general  observations,  I  should  mention 
habitat :  Danneus  geniculatus  and  D.  clavipes,  the  genus  Hoplo- 
phora,  and  some  others,  live  chiefly  under  bark,  and  more  especially 
in  decaying  wood ;  some  of  the  genus  Orihata  may  be  found  on  the 
leaves  of  trees,  but  the  greater  number  of  the  Orihatidse  are  more 
or  less  sohtary,  and  live  either  in  moss,  preferring  that  growing 
on  the  lower  parts  of  trees,  or  under  stones,  but  I  have  found 
them  most  numerous  upon  some  of  the  parasitic  fungi  which  grow 
out  from  the  stems  of  trees  in  woods ;  this  is  specially  the  case  with 
Tegeocranus,  The  moss  must  be  damp  but  not  wet ;  I  have  found 
but  few  when  it  was  either  very  wet  or  very  dry. 

Transformations. 

I  consider  that  the  most  interesting  work  that  I  have  done  for 
this  paper  in  this  department  is  in  tracing  the  transformations  and 
life-history  of  Tegeocranus  latus,  the  larva  and  nymph  of  which  have 
not,  to  my  knowledge,  been  before  observed,  and  are  remarkable 
creatures ;  indeed,  I  fancy  that  those  who  look  at  the  nymph  and 
perfect  creature  will  agree  with  me  that  no  more  singular  trans- 
formation exists  amongst  the  Acarina. 

The  mode  of  watching  transformations  which  I  have  adopted 
has  been  much  the  same  as  I  employed  in  breeding  Cheyleti  and 
Glyciphagi;  I  have  succeeded  better  with  a  simple  glass  ring  cell 
with  a  loose  thin  cover  kept  on  by  a  clip,  than  with  more  elaborate 
or  more  perfect  apparatus ;  into  each  cell  a  small  piece  of  moss  or 
decayed  wood  was  placed,  having  been  first  carefully  examined 
under  the  Microscope  to  see  that  it  did  not  contain  mites  or  ova, 
then  the  mites  to  be  studied  were  carefully  picked  in  one  by  one, 
only  one  sort  being  placed  in  a  cell,  and  only  a  few  specimens; 
each  cell  was  examined  every  day,  and  air  and  moisture  given  when 
necessary.  When  I  was  fortunate  enough  to  find  a  captive  com- 
mencing its  transformation,  the  whole  apparatus  was  transferred  to 
the  stage  of  the  Microscope  and  the  change  watched ;  I  have  usually 
kept  some  twenty-five  to  thirty  of  these  breeding  cages  going 
through  the  past  summer,  but  have  found  great  difficulty  in 
keeping  some  species,  and  have  not  succeeded  in  getting  them  to 
lay  eggs,  although  I  have  bred  through  from  eggs  and  larvae  which 
I  have  found,* 

The  escape  of  the  larva  from  the  egg  I  have  watched  in  the 

*  Since  this  paper  has  been  lodged  with  the  Society  I  have  succeeded  in  the 
case  of  Tegeocranus  coriaceus. 


232  Transactions  of  the  Society. 

case  of  Damseus  geniculatus  and  D.  clavipes;  the  egg  in  these 
species  is  an  oval  somewhat  flattened  on  two  sides ;  it  is  brown,  but 
round  the  edge  runs  a  lighter  band  where  it  seems  that  the  shell  is 
thinner ;  along  this  band  the  shell  breaks,  finally  separating  into  two 
boat-like  pieces  ;  it  breaks  first  at  the  small  end,  which  contains  the 
head,  or  rather  rostrum,  of  the  larva;  the  long  legs  are  doubly- 
folded  upon  the  under  side  of  the  body;  the  long  hairs  of  the  back  lie 
flat  and  pointing  straight  backwards ;  the  front  part  of  the  cephalo- 
thorax,  when  I  watched  the  process,  protruded  first ;  it  was  slowly 
followed  by  the  anterior  pair  of  legs ;  then  the  whole  cephalothorax 
aud  the  second  pair  of  legs  gradually  made  their  appearance,  the 
progress  being  very  slow ;  a  long  delay  then  seemed  to  take  place, 
during  which  the  various  parts  stifiened  and  assumed  their  normal 
positions,  the  hairs  becoming  more  or  less  perpendicular ;  the  hinder 
pair  of  legs  (for  the  larva  is  hexapod)  remained  in  the  shell  until 
the  last,  and  pushing  against  the  inside  of  one  half,  while  the  back 
rested  in  the  other,  seemed  slowly  to  open  it.  As  the  difierent 
parts  emerged,  everything  movable  was  kept  continually  moving,  a 
strange  sight  in  these  slow  and  lazy  creatures;  the  legs  were 
worked  in  all  directions,  and  it  was  amusing  to  watch  the  parts  of 
the  mouth  constantly  going  ;  the  lobster-like  mandibles,  usually  so 
difficult  to  see,  were  protruded  and  retracted  independently,  and 
kept  snapping  continually.  The  escape  from  the  egg  lasted  six  or 
eight  hours  ;  I  cannot  say  if  it  takes  as  long  in  a  state  of  nature. 

The  change  from  the  larval  to  the  nymph  stage  does  not  offer 
any  sufficient  difference  from  that  from  nymph  to  perfect  creature 
to  make  it  necessary  to  describe  it.  Claparede  {loe.  cit.)  in  his 
admirable  papers  on  the  Acarina  describes  how  he  watched  the 
transformations  of  water  mites  of  the  genus  Atax,  and  found  that, 
on  the  change  from  larva  to  nymph  and  from  nymph  to  perfect 
creature,  it  was  not  a  mere  change  of  skin  that  was  eff'ected,  but 
that  the  whole  creature  dissolved,  the  new  creature  being  formed 
from  the  material,  the  skin  of  the  old  creature  coming  away  and 
leaving  an  egg-shaped  body,  long  before  the  new  creature  was  fully 
developed.  More  lately  Megnin  has  traced  the  development  of  the 
Sarcoptidss  and  Gamasinm  with  precisely  the  same  result  as 
Claparede. 

I  am  not  aware  that  anyone  has  previously  watched  the 
Orihatidee,  but  my  own  observations  upon  them  certainly  lead  me 
to  the  same  conclusion.  It  must  not,  however,  be  forgotten  that 
Duges,  in  his  excellent  chapter  on  the  Hydrachnidm,  the  trans- 
formations of  which  he  watched,  expresses  a  contrary  opinion,  and 
says  that  the  creature  retires  within  its  own  skin  as  within  a  bag, 
and  that  the  parts  are  modified  rather  than  newly  formed ;  and  he 
says,  in  support  of  this  view,  that  mutilated  parts  do  not  reappear. 
Probably  the  real  divergence  of  opinion  is  not  so  great  as  it  seems, 


British  Orihatidw.     By  A.  D.  Michael.  233 

as  Duges  describes  a  partial  dissolution,  although  he  thinks  that 
the  legs,  for  instance,  are  formed  at  the  expense  of  the  old  legs 
instead  of  from  the  general  mass  of  the  body,  which  Megnin 
denies,  and  which  does  not  coincide  with  my  own  opinion. 

As  a  rule,  the  integument  of  the  larva  and  nymph  of  the 
Orihatidm  is  soft  and  light-coloured ;  in  the  perfect  creature  it  is 
hard  and  dark ;  this  is  subject  to  the  modification  hereafter 
mentioned. 

In  the  final  change,  which  I  have  carefully  watched  in  the  case 
of  Tegeocranus  latus  and  Oribata  punctata,  the  adult  nymph 
gradually  becomes  inert,  creeps  into  a  hole  or  sheltered  place,  and 
seems  to  me  to  fix  its  claws  firmly  in  whatever  it  is  resting  on ;  it 
then  becomes  motionless  and  to  all  appearance  dead.  In  one  or 
two  instances  with  Tegeocranus  latus  I  carefully  cut  out  the  minute 
piece  it  was  fixed  on,  and  placed  it  where  I  could  see  it  better, 
preserving  the  same  conditions ;  in  this  state  it  remained  for  about 
a  fortnight  without  any  signs  of  life,  at  the  end  of  that  time  the 
skin  got  rapidly  darker,  and  about  twelve  hours  after,  the  skin 
split  at  the  posterior  edge  (the  creature  being  a  flat  oval)  and  the 
anal  margin  of  the  body  of  the  adult  slowly  appeared  by  the  skin 
shrinking  from  it ;  this  splitting  along  the  edge  and  shrinking  of 
the  skin  imperceptibly  proceeded  from  behind  forward,  the  creature 
remaining  motionless.  After  five  or  six  hours  one  could  see  that 
the  parts  of  the  perfect  creatiu-e  were  formed  independently  of  the 
similar  parts  of  the  nymph,  the  legs,  for  instance,  not  being  formed 
within  the  old  legs  which  were  stretched  out,  but  being  folded  on 
the  body  and  secm*ely  packed  within  the  depressions  between  the 
protecting  ridges  before  mentioned.  When  the  skin  had  split 
sufficiently  far,  the  perfect  creature  at  last  moved,  slowly  unfolded 
its  legs,  withdrew  its  cephalothorax  from  the  fore  part  of  the  old 
skin,  like  a  finger  from  a  glove,  and  walked  off,  leaving  the  old  skin 
with  outstretched  legs  in  the  same  position  it  had  occupied  for  a 
fortnight. 

With  regard  to  the  discovery  of  the  nymph  of  Tegeocranus 
latus,  one  day,  when  searching  for  Oribatidse  amongst  moss  on  an 
old  tree  stump  in  Epping  Forest,  I  found  between  the  moss  and  the 
wood  a  creature  new  to  me.  On  examining  it  under  the  Microscope, 
I  found  that  it  belonged  to  the  family  I  wanted,  but  was  so  strange 
and  bizarre  that  I  hardly  knew  how  to  class  it ;  it  was  a  flat  oval, 
the  edge  cut  into  great  triple  serrations  difficult  to  describe,  and  from 
each  serration  sprang  a  long  thick  spine,  bent  into  an  elegant 
double  curve  and  armed  with  short  thorns,  while  ring  within  ring 
on  the  back  were  the  cast  dorsal  skins  of  the  earlier  stages,  each 
bearing  its  own  serrations  and  spines,  so  that  the  whole  dorsal 
surface  was  a  chevaux-de-frise,  the  ventral  surface  being  pressed 
close  to  the  wood.     At  once  there  arose  the  question,  was  this 


234  Transactions  of  the  Society. 

strange  organism  a  nymph  or  a  perfect  form  ?  As  before  stated,  the 
nymphs  are  usually  soft  and  light-coloured,  the  perfect  form  hard 
and  dark,  but  this  is  modified  by  the  fact  that  with  each  change  of 
skin  the  nymph  becomes  somewhat  harder  and  darker,  so  that  the 
nymph  of  a  species,  the  adult  of  which  is  very  black  and  hard,  as  in 
the  legeocrani,  becomes,  before  the  final  change,  as  dark  and  hard 
as  some  other  species,  e.  g.  many  of  the  genera  Nothrus  and 
Eremseus,  are  after  it.  To  decide  this  I  searched  and  at  last  obtained 
several  more  living  specimens  of  various  ages ;  some  appeared  to 
show  eggs,  which  strongly  favoured  the  idea  that  it  was  an  adult, 
as  the  appearance  somewhat  indicated.  1  also  obtained  ^some  cast 
skins.  WhUe  in  doubt,  I  received  a  letter  from  ]\Ir.  George,  with  a 
rough  sketch  of  something  he  had  found,  which  was  manifestly  my 
creature ;  he  had  only  one  specimen,  and,  like  myself,  was  in  doubt 
whether  it  was  a  nymph  or  adult ;  his  individual  showed  eggs,  which 
pointed  to  the  adult  theory.  I  kept  all  I  could  get  alive  for  some 
weeks  without  any  indication  of  a  more  perfect  stage  ;  still  I  could 
not  rid  myself  of  the  idea  that  it  was  only  a  nymph,  my  reasons 
being,  first,  that  it  bore  on  its  back  the  dorsal  parts  of  the  larval 
and  two  pupal  skins  only,  and  in  Nothrus  fhelejyroetus  and  others 
that  I  had  watched,  the  nymph  had  cast  its  skin  twice  before  the 
change  to  the  perfect  form ;  secondly,  that  I  found  what  seemed 
to  be  a  discarded  skin  as  perfect  as  the  animal  I  had  alive;  if  it 
were,  something  must  have  come  out  of  it ;  thirdly,  I  had  one  dead 
specimen  which  seemed  to  show  something  forming  below  the  skin. 
I  kept  my  breeding  cages  going  until  the  last  day  of  my  stay  in 
Epping  Forest,  without  success  ;  but  the  evening  before  I  left,  one 
became  much  darker,  and  the  morning  I  was  leaving  for  the 
Highlands  the  skin  of  the  nymph  split,  and  Tegeocranus  lotus 
emerged  as  before  described. 

I  relate  this  to  show  the  necessity  for  caution  in  judging  whether 
a  newly  found  mite  is  a  nymph  or  perfect  creature,  and  how  excu- 
sable it  was  in  Koch  to  figure  them  often  as  separate  species,  writing 
when  he  did. 

I  have  mentioned  above  that  some  specimens  apparently  contain 
eggs ;  it  is  quite  possible  that  Mr.  George  and  I  were  mistaken,  and 
that  they  were  not  eggs ;  their  being  so  seems  inconsistent  with  the 
dissolution  and  reformation  of  the  animal  in  the  change  from  nymph 
to  imago ;  but  it  must  be  remembered  that  0.  Kobin  has  shown  * 
that  the  male  Dermaleichi  copulate,  not  with  the  final  form  of  female, 
but  with  an  intermediate  form,  which  in  appearance  almost  exactly 
resembles  the  nymph ;  and  the  same  author  and  Megnin  have  de- 
monstrated that  this  intermediate  form,  which  they  call  " femelle 
accoujyJee,''  often  shows  eggs,  although  not  provided  with  any  vulva 
of  gestation,  which  only  appears  in  the  final  form  of  female.  This 
*  '  Comptcs  Keiidus,'  1868,  p.  776. 


British  Oribatidte.     By  A.  D.  Michael.  235 

is  asserted  by  Megnin  to  apply  to  the  Tyroglyphi,  Glyciphagi, 
Carpoglyphi,  Gamasinse,  and  Tromhididx :  it  would  therefore 
from  analogy  be  likely  to  occur  in  the  Orihatidee,  although  I  am 
not  aware  that  it  has  been  observed,  and  if  so  these  may  well  have 
heeB.  femelles  accouflees,  or,  as  1  should  call  them,  nubile  females. 

I  was  curious  to  see  how  the  casting  of  the  skin  was  so 
managed  as  to  leave  the  pile  of  the  dorsal  parts  on  the  back,  and 
thought  this  a  favourable  species  to  observe.  I  did  not  find  any 
difficulty  in  doing  so.  The  skin  splits  along  the  edge,  commencing 
at  the  rear  as  before  described,  until  it  reaches  the  rear  of  the  ver- 
tex ;  then  the  split,  instead  of  continuing  round  the  edge  of  the 
cephalothorax,  goes  across  the  back,  and  the  creature  backs  out  of 
the  fore  and  lower  part  of  the  old  skin,  keeping  the  dorsal,  or  rather 
dorso-abdominal,  portion  still  on  its  back.  There  does  not  appear 
to  me  to  be  any  disintegration  of  the  creature  in  mere  changes  of 
skin.  Every  larva  or  nymph  which  I  have  figured  or  mentioned  I 
have  assui'ed  myself  of  by  breeding  it  to  the  perfect  form. 

Organs  of  Special  Sense. 

As  before  stated,  Oribatidx  have  not  any  visible  eyes  that  have 
yet  been  discovered.  I  have  before  expressed  an  opinion  that 
others  of  the  Acarina  whose  condition  is  similar  have  some  sense 
of  sight,  or  are,  at  all  events,  sensitive  to  light,  which  most  of  them 
dislike ;  in  order  to  utilize  this  dislike  in  tracing  sight  further  if 
possible,  I  placed  a  living  Eremseus  ohlongus,  one  of  the  most  lively 
of  the  Orihatidee,  in  a  large  glass  cell,  putting  a  piece  of  moss  in 
the  middle.  I  then  arranged  the  Microscope  so  that  the  sun  fell  on 
the  stage,  but  placed  a  dark  screen  to  throw  it  into  shadow.  I  then 
placed  the  cell  on  the  stage,  and  watched  until  the  mite  was  on  the 
raised  edge  of  the  cell,  where  they  generally  hke  to  be.  I  then 
suddenly  removed  the  screen ;  the  mite  did  not  wander  vaguely 
about,  but  came  down  from  the  edge,  and  crossed  the  bottom  of  the 
cell  in  a  straight  hne  for  the  moss,  under  which  he  got ;  the  same 
experiment  repeated  once  or  twice  had  the  same  result.  I  leave 
my  hearers  to  decide  whether  this  does  not  indicate  some  sense  of 
sight. 

"What  are  called  the  protecting  hairs  of  the  stigmata  were  once 
supposed  to  be  organs  of  vision  ;  this  was  evidently  incorrect,  and 
is  long  since  exploded.  The  high  authority  of  Nicolet  and  others 
is  in  favour  of  their  being  simply  protecting  hairs.  Doubtless  the 
contrivances  by  which  stigmata  and  spu'acles  are  protected  are  various, 
but  it  is  generally  apparent  that  they  are  admirably  suited  to  their 
purpose.  It  is  not,  however,  at  all  clear  how  these  hairs  can  be  of 
any  protection ;  there  is  never  more  than  one  on  each  side ;  they 
cannot  exclude  dust,  &c.,  because  whatever  the  form  of  the  hair, 
only  the  fine  part  is  near  the  stigmatic  opening,  and  they  are  too 


230  Transactions  of  the  Society. 

soft  and  flexible  to  be  effective  defensive  weapons ;  whereas  the  joints 
of  the  legs  are  often  defended  by  powerful  spikes ;  the  clubbed  ends 
borne  by  so  many  of  these  hairs  are  often  hollow  or  cellular,  and  it 
seems  possible  that  they  may  be  eventually  found  to  be  the  seats  of 
some  special  sense  (as  hearing  or  smellj  instead  of  being  merely 
protective. 

Summary. 

The  results  of  the  season's  work  may  be  summarized  thus :  forty- 
four  species  have  been  found,  of  which  I  believe  that  only  three  or 
four  have  been  previously  recorded  in  Britain.  The  total  number 
which  rewarded  Nicolet's  admirable  and  prolonged  search  in  France 
was  fifty-six. 

Of  these  forty- four  species,  I  believe  three  to  be  entirely  new 
to  science,  viz.  Nos.  21,  38,  39. 

Two  species  have,  to  my  knowledge,  been  found  in  France, 
Germany,  and  Sweden,  viz.  Nos.  2  and  32. 

Eighteen  species  in  France  and  Germany,  viz.  Nos.  3,  5,  13, 
15,  17,  22,  24,  25,  26,  27,  29,  31,  32,  33,  36,  40,  43,  44. 

Fourteen  species  in  France  only,  viz.  Nos.  1,  4,  6,  8,  10,  11, 
12,  14,  16,  18,  23,  28,  41,  42. 

Six  species  in  Germany  only,  viz.  Nos.  9,  19,  20,  34,  35,  37. 
I  include  Switzerland  with  Germany  for  this  purpose. 

One  species  in  France  and  Algeria,  viz.  No.  7  ;  probably  they 
would  have  been  found  elsewhere  if  properly  looked  for,  as  two  or 
three  have  also  been  found  in  Sj^itzbergen. 

The  life-history  of  two  sorts,  Tegeocranus  latus  and  Nothrus 
tlieleproctus,  has  been  traced  for  the  first  time,  and  others  confirmed, 
in  addition  to  the  above  observations  on  habits,  &c. 

Part  II. 

In  this  part  the  following  rules  have  been  observed  : — 

Species  which  have  been  described  by  Nicolet  are  not  redescribed, 
but  those  given  by  Koch  or  others  are  described  where  the  descrip- 
tion of  the  author  referred  to  does  not  seem  to  me  sufficient  for 
certain  identification.     Species  believed  to  be  new  are  described. 

If  there  be  fair  grounds  for  believing  that  a  species  found  by 
me  is  identical  with,  or  a  slight  variety  of,  one  known  by  me  to 
have  been  already  described,  that  species  is  adopted  (defining  it) 
instead  of  giving  a  new  name,  although  the  former  description  may 
not  be  sufficient  for  actual  certainty. 

With  regard  to  naming  the  joints  of  the  legs,  Bobin  is  followed, 
not  Nicolet ;  this  I  have  done,  regarding  Robin  as  the  more  eminent 
anatomist  as  well  as  the  more  modern  authority.  It  must  be  remem- 
bered that  their  views  are  entirely  different,  c.  g.  the  trochanter  of 


British  Oribatidie.     By  A.  B.  Michael  237 

Kobin  is  ihefemm-al  of  Nicolet ;  in  other  respects,  Nicolet's  names 
for  parts  of  the  exo-skeleton  are  preserved. 

The  sexes  are  not  described  separately,  their  external  differences 
being  usually  so  slight  that  it  is  unnecessary. 

All  measurements  are  in  decimals  of  a  millimetre. 

A  reference  to  Koch  without  naming  the  work  means  his 
*  Deutschland's  Crustaceen  Miriapoden  und  Arachniden,'  Kegens- 
burg,  1841. 

In  the  Plates,  all  whole  creatures  are  drawn  x  65,  most  details 
are  x  300. 

All  the  figures  are  drawn  from  nature,  except  Figures  4  and  5, 
Plate  IX. 

All  whole  creatures  were  drawn  in  the  first  instance  with  the 
camera. 

GENUS  PELOPS. 

1.  Pelops  faeinosus.     Nic. 

Nic.  425. 

Found  at  Kirton  Lindsey  by  Mr.  George,  and  by  me  at  Epping 
Forest  and  Loch  Maree ;  not  uncommon. 

The  Enghsh  specimens  have  not  the  round  spot  in  the  centre 
of  the  abdomen  figured  by  Nicolet,  nor  the  two  spatulate  hairs  one 
on  each  side  of  it,  and  the  stigmata  are  not  as  deeply  sunk  as  in 
Nicolet's  drawing.  It  might  be  said  these  differences  are  sufficient 
to  constitute  a  species,  but  in  the  absence  of  further  evidence,  I 
prefer  considering  them  as  showing  a  variety  only. 

GENUS  OEIBATA. 

2.  Okie  AT  A  alata.     Herm. 
Notaspis  alatus.     Hermann,  '  Memoire  Apterologique.' 

,,  „  Duges,  3rd  Memoire,  47. 

Acarus  eoleoptratus.     Linnaeus,  2nd  edn.  No.,  1973. 
Zetes  dorsalis.     Koch,  fasc.  2,  pi.  14. 
Orihata  alata.     Gervais, '  Histoire  Nat.  des  Apteres,'  vol.  iii.  258. 

„  „         Nicolet,  'Hist.  Nat.  des  Acariens,'  &c.,  431. 

Found  by  Mr.  George  at  Kirton  Lindsey,  and  by  me  at  Epping 
Forest. 

3.  Oribata  Lucasii.     Nic. 

Nic.  432. 
Zetes  Isevigatus.     Koch,  fasc.  3,  pi.  8. 
Found  at  Epping  Forest. 

4.  Oribata  nitens.     Nic. 

Nic.  433. 
Found  at  Epping  Forest. 


238  Transactions  of  the  Societij. 

5.  Okibata  punctata.     Nic. 

Orihates  ovalis.     Koch,  fasc.  3,  pi.  5. 
Orihata  punctata.     Nic.  434. 
Nymph  and  perfect  creature  found  everywhere ;    common.     I 
have  hred  this  creature  through  its  changes,  and  can  confirm  the 
correctness  of  Kicolet's  figure  of  the  nymph. 

I  use  Nicolet's  name  of  imnciata  instead  of  Koch's  earher 
name  of  ovalis,  because  the  latter  author  gives  an  Orihates  ovalis 
and  an  Orihates  ovatus,  which  might  cause  confusion. 

6.  Oribata  pikiformis.     Nic, 
Nic.  436. 
Found  at  Epping  Forest  and  Loch  Maree ;  scarce. 
In  the  English  specimens  the  stigmatic  hairs  are  more  strongly 
and  suddenly  clubbed  than  in  Nicolet's  figure. 

7.  Oribata  lapidaria.     Lucas. 
Lucas,  '  Exploration  scientifique  de  I'Algerie,'  318. 
Nic.  439. 
Found  on  trees  everywhere  ;  very  common. 
I  think  it  possible  that  this  and  Orihata  glohula,  Nic,  may  turn 
out  to  be  one  species ;  certainly  some  of  w  hat  I  have  found  are 
forms  intermediate  between  the  two  types. 

8.  Oribata  Edwardsii.     Nic. 
Nic.  438. 
Found  at  Loch  Maree. 

9.  Oribata  mollicomus.     Koch. 

Orihates  mollicomus.     Koch,  fasc.  30,  pi.  20. 

Orihata  notata.  Thorell,  '  Oefvers.  af  Kongl.  Vet.-Akad.'  1871, 
695. 

I  have  found  three  or  four  specimens  of  what  appears  to  be 
this  creature  at  Epping  Forest.  It  is  quite  possible  that  it  is  not 
truly  a  species,  but  only  another  variety  of  Orihates  setosus  (Koch, 
fasc.  30,  pi.  19  ;  Nic.  436) ;  in  which  case  it  is  better  that  the  latter 
name  should  stand  as  Nicolet  has  adopted  it ;  but  the  reasons  against 
this  are.  Firstly,  in  my  specimens  the  wings  of  the  tectum  are  not 
joined  by  any  transverse  ridge — a  distinction  by  no  means  unim- 
portant, as  Nicolet  relies  greatly  on  this  ridge ;  Secondly,  my  speci- 
mens are  much  smaller  than  Nicolet's ;  Thirdly,  the  rows  of  hairs 
on  the  back  are  much  wider  apart  from  row  to  row,  and  contain 
fewer  hairs  than  in  Nicolet's  figure ;  Fourthly,  the  coxae  and  tro- 


British  Orihatidse.     By  A.  D.  Michael.  239 

chanters  of  the  first  two  pairs  of  legs  in  my  specimens  are  prolonged 
at  the  edge  into  thin  flat  blades  not  mentioned  by  Nicolet. 

I  think  this  is  proVjably  the  species  recorded  by  Thorell  as  found 
at  Bell's  Sound,  Spitzbergen. 

10.  Oribata  globula.     Nic. 
Nic.  43  \ 
One  specimen  found  at  Epping  Forest. 

GENUS  LEIOSOMA. 
11.  Leiosoma  nitens,     Gervais. 

Oribata  nitens.     Gervais,  in  Walckenaer,  vol.  iii.  p.  259. 
Leiosoma  nitens.     Nic.  441. 

Found  by  Mr.  George  at  Kirton  Lindsey. 

12.  Leiosoma  similis.     Nic. 

Nic.  442. 
Everywhere;  common. 

In  English  specimens  the  central  point  of  the  tectum  is  not  as 
sharp  as  in  Nicolet's  figure,  but  is  more  square. 

13.  Leiosoma  ovata.     Koch. 

Leiosoma  lativentris.     Nic.  443. 
Oribates  ovatus.     Koch,  fasc.  30,  pi.  24. 

Found  at  Epping  Forest  and  Loch  Maree. 

The  English  specimens  seem  much  smaller  than  the  size  given 
by  Nicolet  ('55  mm.  instead  of  "75  mm.),  but  as  they  agree  in  all 
other  respects  I  do  not  think  this  sufficient  to  found  a  species. 

14.  Leiosoma  miceocephala.    Nic. 
Nic.  443. 
Found  at  Epping  Forest ;  scarce. 

GENUS  CEPHEUS. 
15.  Cepheus  tegeocranus.     Herm.  93. 

Notasjpis  tegeocranus.     Gervais,  in  Walck.  iii.  258. 
Cepheus  vulgaris.     Nic.  445. 

Found  everywhere ;  common. 

In  the  English  specimens  the  rows  of  hairs  on  the  abdomen 
are  not  nearly  so  conspicuous  as  they  are  in  Nicolet's  plate. 


240  Transactions  of  the  Society. 

16.  Cepheus  latus.     Nic. 
Nic.  446. 
Found  at  Epping  Forest. 

The  English  specimens  have  small  hairs  on  the  abdomen,  not 
figured  by  Nicolet,  and  the  anterior  line  of  tbe  abdomen  is  very 
slightly  sinuated.  I  cannot  help  doubting  whether  the  species  is 
really  more  than  a  variety  of  C.  tegeocranus. 

GENUS  NOTASPIS. 

17.  NoTASPis  BiPiLis.     Herm. 

Hermann,  95. 

Nic.  448. 
Or  {bates  hadius  ?     Koch,  fasc.  30,  pi.  23. 
Oppia  cornuta.  „         „  38,  pi.  8. 

Oribata  hipilis.     Gervais,  vol.  iii.  p.  259. 
Found  everywhere ;  common. 

18.  NoTASPis  ExiLis.     Nic. 
Nic.  448. 
Found  everywhere ;  common. 

The  small  hairs  on  the  abdomen  figured  by  Nicolet  are  absent, 
or  very  inconspicuous,  in  the  English  specimen. 
Is  Nicolet's  N.  tibialis  really  a  distinct  species  ? 

19.  NoTASPis  PiLOsus.     Koch. 

Zetes  pilosus.     Koch,  fasc.  31,  pi.  12. 
„    pilosulus.      „     Uebersicht,  101. 
Average  length  about  '45  mm. 
„       breadth    „       "3  mm. 
Found  at  Epping  Forest ;  scarce. 

This  and  the  next  species  clearly  should  not  have  been  included 
in  Koch's  genus  Zetes,  which  Nicolet  has  properly  joined  to  Oribata. 
I  have  had  great  doubt  if  they  are  really  distinct,  but  on  the  whole 
I  think  that  the  difference  in  the  so-called  stigmatic  hairs,  which 
are  good  specific  distinctions  in  the  Orihatidm,  the  smaller  size  and 
rounder  shape  of  the  body,  and  the  far  greater  development  of  the 
general  dorsal  hairs  in  this  species,  are  sufficient  to  justify  both 
being  retained,  subject  to  future  investigation ;  this  one,  at  all 
events,  should  stand. 

Colour  red-brown,  sometimes  almost  red.  Gephalotliorax  conical, 
with  a  constriction  a  short  distance  from  the  front,  thence  it  curves 
outwards  until  about  the  middle,  whence  the  central  portion  runs 
nearly  straight  back  rising  to  the  level  of  the  abdomen ;  the  lateral 


British  Oribatidse.     By  A.  D.  Michael.  241 

portions  are  much  lower  in  level,  and  expand  into  a  shelf  with 
deepish  indentations  for  the  insertion  of  first  pair  of  legs  and 
shallower  ones  for  the  second  pair.  Tectum  so  entirely  amalga- 
mated with  cephcdotliorax  that  it  is  only  shown  by  two  strong 
spinose  bristles  standing  up  at  its  termination ;  two  similar  bristles 
stand  up  straight  behind  the  first  pair,  just  at  the  hind  margin  of 
the  vertex,  two  shorter  similar  ones  horizontal  at  the  above-named 
constrictions ;  stigmata  at  the  edge  of  the  raised  jmrt  of  cephalo- 
thorax  almost  under  the  edge  of  the  alidomen ;  the  stigmatic  hairs 
medium  length,  standing  upwards  and  slightly  outwards,  filiform, 
about  half  the  length,  thence  spatulate  with  blunt-pointed  tips. 
Mandibles  large  and  projecting. 

Abdomen  a  short  pear-shape,  hinder  end  very  round,  anterior 
end  narrow,  with  a  rounded  point  projecting  on  to  cephalothorax 
and  joined  to  it  on  a  level ;  a  strong  spike  stands  straight  out 
horizontally  from  each  edge  of  the  dorsal  plate  between  the  second 
and  third  pairs  of  legs.  A  row  of  about  seven  very  long  hairs 
(nearly  half  as  long  as  the  abdomen)  curved  backwards  round  edge 
of  each  side  of  abdomen ;  six  similar  round  hind  margin  lower  in 
level,  and  three  pairs  down  back  more  central ;  coxae  of  first  two 
pairs  of  legs  hidden,  those  of  two  hind  pairs  conspicuous;  all 
trochanters  stout,  claws  large. 

20.  NoTASPis  LUCORUM.     Koch. 
Zetes  lucorum.     Koch,  fasc.  31,  pi.  18. 

Average  length  about  *  67  mm.,  but  variable  breadth  about 
"37  mm. 

A  creature  which  I  believe,  not  without  doubt,  to  be  Koch's 
lucorum,  has  been  found  by  Mr.  George  at  Kirton  Lindsey,  and  by 
me  at  Epping  and  Loch  Maree ;  it  had,  however,  been  previously 
found  by  Mr.  Underbill,  of  Oxford,  and  figured  by  him  in  the 
'  Notes  of  the  Postal  Microscopic  Club,'  December  tilth,  1877.  It  is 
a  very  variable  species,  the  abdomen  in  some  specimens,  being  con- 
siderably longer  in  shape  than  in  others.  The  distinctions  from 
the  last  species  are,  its  larger  size  and  more  pointed  abdomen,  the 
stigmatic  hairs  being  much  shorter,  and  instead  of  being  spatulate 
having  a  short  filiform  stalk  terminated  by  a  piriform  club,  so  short 
as  usually  to  appear  a  ball  which  hardly  rises  above  the  Imck,  and 
that  the  dorsal  hairs  are  much  shorter. 

GENUS  SCUTOYERTEX.*     Mihi. 

This  genus  I  have,  somewhat  unwillingly,  originated,  for  a 
creature  which  has  not,  to  my  knowledge,  been  recorded  before,  and 
which,  although  bearing  many  resemblances  to  Eremicus,  is  so 
opposed  to  some  of  the  main  characteristics  by  which  Nicolet  defines 

*  Sndum,  a  shield,  and  vertex,  the  top  of  the  head. 
VOL.    II.  R 


242  Transactions  of  the  Society. 

that  genus,  that  it  appears  to  me  that  it  cannot  properly  be  included 
therein. 

Generic  Characters. 

Palpi  with  first  joint  small,  second  and  third  swollen,  the 
second  being  considerably  the  longest ;  fourth  and  fifth  joints  much 
slighter,  but  fifth  as  long  as  second,  and  dentated  on  the  outer 
edge.  Labium  broader  than  long,  nearly  straight  on  the  anterior 
edge,  and  not  covering  above  half  the  buccal  opening.  Mandibles 
rather  long  with  the  fixed  claw  not  toothed.  Maxillse  bilobed,  lobes 
unequal.  Gephalothorax  large  and  conical,  having  a  tectum  attached 
only  by  its  base,  less  wide  than  the  cephalothorax,  and  covering  part 
only  of  its  length.  Cephalothorax  deeply  indented  for  the  recep- 
tion of  the  coxae  of  the  first  pair  of  legs,  which  are  almost  entirely 
hidden,  those  of  the  second  pair  being  supported  by  strong  projec- 
tions. Legs  thick  and  shorter  than  the  body ;  all  the  trochanters  and 
the  coxse  of  the  last  two  pairs  broad  and  flattened ;  fourth  joints  of 
the  first  pair  of  legs  with  a  projection  overhanging  the  fifth  like  Ere- 
mseus.  Tarsi  with  three  heterodactyle  claws,  the  centre  one  being 
conspicuously  the  thickest.  Abdomen  longer  than  broad,  flattened 
on  the  dorsal  surface,  the  dorsal  plate  of  which  projects  anteriorly 
over  the  cephalothorax,  and  may  be  fastened  to  the  upper  surface 
of  the  tectum,  and  also  projects  at  the  anterior  angles  (or  shoulders) 
sheltering  the  stigmata,  which  are  wide  apart,  set  far  back,  and 
point  outwards. 

This  genus  will  fall  in  Nicolet's  first  division,  being  tridactyle ; 
in  the  first  subdivision,  being  furnished  with  a  tectum,  and  it  would 
appear  to  come  properly  at  the  end  of  that  division  immediately 
before  Eremseus,  which  latter  genus  it  resembles  in  the  form  of  the 
tarsi  and  claws,  the  mode  of  insertion  of  the  legs,  and  many  other 
particulars,  while  it  is  divided  from  it  by  the  tectum,  the  form  of 
the  palpi  and  labium,  the  thickness  of  the  legs,  &c. 

21.  ScuTO VERTEX  scuLPTus.     Mihi  (Plate  XI.  Fig.  4). 

Average  length  about  •  60  mm. 
„       breadth    „      '33    „ 
NeiD  Species. 
Colour  varying  from  dark  red  brown  to  black. 
Cephalothorax  large  at  the  base  and  bluntly  conical,  but  mostly 
hidden  under  the  advancing  dorsal  plate  of  the  abdomen.     Tectum 
almost  square,  but  a  little  longer  than  wide ;    wings  of  tectum 
raised  almost,  perpendicularly,  broadest  anteriorly,  and  ending  in 
long,  blunt,  curved  points,  with  curved  terminal  hairs.    A  little  way 
in  front  of  the  tectum  is  a  round  plate  covering  the  point  of  the 
rostrum,  and  raised  in  the  centre  and  at  the  edge.     From  below 
this  a  ridge  runs  along  the  side  of  the  cephalothorax,  ending  in  a 


British  Oribatidx.     Bij  A.  D.  Michael.  243 

rounded  elevation  before  reaching  the  first  pair  of  legs.  These  are 
set  in  deep  clefts  of  the  sternum,  open  above,  and  open,  but  to  a  less 
extent,  below.  Between  the  second  and  third  pairs  of  legs,  is  a 
long,  chitinous  projection  of  the  sternum,  bifid  at  the  end.  Stig- 
matic  hairs  medium  length,  slightly  spatulate  at  the  ends,  where 
they  are  roughened  with  small  points ;  cephalothorax  and  tectum 
covered  with  evenly-scattered,  rough,  elevated  spots ;  wings  of 
tectum  reticulated  with  small  raised  ridges ;  all  joints  of  the  legs, 
except  the  tarsi,  thick,  rather  flattened,  broadest  anteriorly,  and 
rough  with  sinuous  ridges.  No  hairs  on  the  vertex,  two  short  ones 
at  the  point  of  the  rostrum,  one  or  two  on  each  of  the  first  four 
joints  of  each  leg,  and  numerous  ones  on  the  tarsus.  Dorsal  plate 
of  the  abdomen  a  long  oval,  rounded  posteriorly,  with  a  waved  edge 
prolonged  anteriorly  over  part  of  the  cephalothorax,  and  ending  in 
a  sharp  point  soklered  to  the  tectum ;  edges  of  the  plate  slightly 
projecting  in  front,  a  narrow  transverse  ridge  near  the  anterior 
point,  from  the  ends  of  which  ridge  other  ridges  start,  nearly  at 
right-angles,  and  then  curve  out  to  the  before-named  projecting 
ridges  :  in  the  centre  of  the  space  between  these  ridges  is  a  light- 
coloured  depressed,  oblong  marking  with  rounded  corners.  This  looks 
clear,  and,  when  the  dorsal  plate  is  removed  and  looked  at  from  the 
inside,  it  is  seen  to  be  due  to  the  chitine  being  absent,  or  extremely 
thin,  there  seeming  to  be  a  membrane  only.  Dorsal  plate  thickly 
dotted  round  the  edges,  but  with  much  larger  elevated  markings, 
having  the  appearance  of  rings  by  transmitted  light,  towards  the 
centre ;  four  small  spatulate  hairs  at  the  anal  margin,  and  two  lines 
of  four  or  five  similar  ones  down  the  back.  Whole  under  surface 
strongly  spotted ;  anal  plates  large,  raised,  and  pentagonal ;  vulval 
plates  nearly  square. 

GENUS  EREMiEUS. 

22.  Eeem^us  oblongus.     Koch. 
Koch,  fasc.  3,  pi.  24. 
Nic.  451. 
Found  everywhere ;  common. 

23.  Erem^us  Cymba.     Nic. 
Nic.  452. 
Found  at  Epping  Forest,  and  near  Tamworth.     Rare. 

GENUS  NOTHRUS. 

24.    NOTHRUS    SPINIGER.       Koch. 

Koch,  fasc.  2,  pi.  18, 
Nic.  455. 
Found  by  Mr.  George  at  Kirton  Lindsey,  and  by  me  at  Epping 
Forest. 

R  2 


244  Transactions  of  the  Sociehj. 

25.  NoTHRUs  HORBiDus,     Herm. 

Notaspis  horridus.     Herm.  90. 
Orihata  horrida.     Gervais,  iii.  254. 
Nothrus  horridus.     Nic.  456. 
Nothrus  runcinatus.    Koch,  fasc.  29,  pi.  23  1  nymph  in  different 
„        sinuatus  „        „      „     „    22  |     stages. 

„        mutilus  „        „      „     „    18     ? 

Found  everywhere. 

It  seems  quite  possible  that  Thorell's  Nothrus  horealis  may 
turn  out  to  be  a  northern  variety  of  this  species. 

26.  Nothrus  bicarinatus.     Koch. 
Koch,  fasc.  29,  pi.  16. 
Nic.  456. 
Nothrus  furcatus.     Koch,  fasc.  30,  pi.  3  )  n 

„       segnis.     Hermann,  94  3  ^    ' 

Found  by  Mr.  George  at  Kirton  Lindsey,  and  by  me  at  Epping 
Forest  and  Loch  Maree. 

27.  Nothrus  palustris.     Koch. 
Koch,  fasc.  29,  pi.  13. 
Nic.  457. 
Nothrus  palUatus.     Koch,  fasc.  29,  pi.  31  >  ■, 

„       histriatus         ,,       „      30    „     4^    -^    -^    * 
Nymi^th  found  by  Mr.  George  at  Kirton  Lindsey  and  by  me  at 
Epping  Forest  and  Loch  Maree :  perfect  creature  found  at  Loch 
Maree. 

28.  Nothrus  nanus.     Nic. 
Nic.  458. 
Found  by  Mr.  George  at  Kirton  Lindsey,  and  by  me  at  Epping 
Forest. 

29.  Nothrus  theleproctus.     Herm.     PI.  X.  Fig.  3. 

Notaspis  theleproctus.     Herm.  91.  j 

Liodes  theleproctus.     Hey  den.  i  carrying  cast  skins. 

Nothrus  theleproctus.      Koch,  fasc.  29,  pi.  10   J 

„        convexus  „        „      „     „     1,  without  cast  skin. 

„       farinosus  „         „      „     ,,     8,   carrying    one    cast 

skin  only. 

„       canaliculatus  „        ,,      „     ,,     7,  washed  clean  ? 

Found  by  Mr.  George  at  Kirton  Lindsey,  and  by  me  at  Epping 
Forest  and  near  Tamworth. 

Koch's  and  Hermann's  descriptions  may  serve  without  repeti- 
tion, as  the  species  is  very  distinct.     It  usually  carries  the  cast 


British  Oribatidw.     By  A.  D.  Michael.  245 

dorsal  skins  flat  on  the  abdomen  concentrically,  hence  the  concen- 
tric horseshoe-shaped  lines  figured  by  those  authors.  The  point 
at  the  anal  end  of  the  abdomen  is  formed  only  by  a  projection  of 
thin  chitine,  and  may  break  away  without  injury  to  the  creature ; 
it  seems  to  me  that  Koch's  canaUculatus,  which  is  founded  on  a 
single  specimen  fished  out  of  water,  may  have  been  theleprodus 
washed  clean,  and  with  the  cast  dorsal  skins  and  anal  projection 
gone.  The  description,  however,  is  not  sufficient  to  make  sure  of 
this. 

The  constriction  in  the  cephalothorax  in  Hermann's  figure  is 
far  too  deep. 

The  larva  of  this  species,  which  I  have  bred,  is  very  light 
brown  ;  cephalothorax  short  and  broad ;  stigmata  very  open,  pointing 
upwards,  and  with  a  serrated  margin ;  stigmatic  hairs  short  and 
spatulate ;  abdomen  much  and  irregularly  wrinkled,  straight  ante- 
riorly, broadest  in  the  middle,  thence  drawn  out  to  a  blunt  point, 
with  two  spatulate  hairs ;  anus  long,  and  about  central  in  the 
abdomen ;  being  usually  far  forward ;  legs  very  short  and  stout, 
with  spatulate  hairs  (see  Plate  X.,  Fig,  2). 

The  nymph  is  almost  similar  to  the  perfect  creature,  but  of 
course  with  a  smaller  number  of  cast  dorsal  skins. 

GENUS  DAM^US. 

30.  Dam^us  geniculatus.     Linn. 
Acarus  geniculatus.     Linn.  vol.  ii.  1025. 

Koch,  fasc.  3,  pi.  13. 
Nic.  460. 

Damieus  iorvus.     Koch,  fasc.  3,  pi.  14.     Nymph. 
Notaspis  clavij^es.     Duges. 

Found  everywhere ;  very  common  under  bark  of  dead  trees,  in 
dead  wood,  &c. 

Great  confusion  has  existed  between  this  species  and  clavipes. 

31.  Dam^us  riparius.     Nic. 
Nic.  461. 

I  found  two  specimens  at  Loch  Maree  of  what  I  think  must  be 
this  species,  although  they  are  rather  smaller  than  the  size  given 
by  Nicolet,  and  the  sinuated  anterior  margin  to  the  abdomen  men- 
tioned by  him  is  hardly,  if  at  all,  shown ;  in  all  other  respects  they 
agree.  I  think  it  better  to  disregard  these  difi'erences,  although 
Nicolet  relies  on  the  sinuated  margin,  than  to  call  these  specimens 
a  new  species ;  the  difi'erence  may  arise  from  locality. 


246  Transactions  of  the  Society. 

32.  Dam^eus  clavipes.     Herm. 

•  Aearus  genicidatus.     Linn.  vol.  ii.  1025. 

Orihata  geniculata.     Fabricius,  '  Ento.  Sys.'  vol.  iv.  431. 
„  „  Latreille,  '  Gen.  Crust,  et  Ins.'  149. 

„  „  Sclirank,  vol.  iii.  208. 

Notaspis  clavipes.        Herm.  88. 
Bamxus  geniculatus.  Koch,  fasc.  3,  pi.  13. 
Aearus  corticalis.        De  Geer,  vol.  vii.  131. 
Bamxus  auritus.       Nic,  463. 
„  „  Murray,  216. 

Found  at  Epping  Forest ;  not  common,  although  Nicolet  says 
it  is  in  France. 

I  have  not  followed  Nicolet's  name,  although  adopted  by  Murray, 
as  I  fail  to  see  why  he  took  the  name  which  Koch  had  given  to  the 
species  Nicolet  calls  riparius,  or  why  Hermann's  far  older  name  of 
clavipes  should  be  discarded ;  no  doubt  the  earlier  writers  did  not 
distinguish  between  this  species  and  geniculatus,  and  included  both 
under  one  description,  but  Hermann's  figure  is  certainly  this  species 
and  Nicolet  says  that  it  is. 

33.  Dam^eus  verticillipes.     Nic. 
Nic.  462. 
JDamseus  nocUpes.     Koch,  fasc.  30,  pi.  6. 

„        onustus.         „        ,,    38,    „    7,  with  coating  of  dirt 

and  cast  skins. 
Found  at  Epping  Forest  and  Loch  Maree. 
Most  of  the  specimens  of  this  creature  which  I  have  found  have 
been  thickly  covered  with  fine  white  dust,  like  pulverulentus  (Koch)  ; 
this  is  not  mentioned  by  Nicolet. 

Dam^eds  nitens.     Koch. 

34.  Oppia  nitens.     Koch,  fasc.  3,  pi.  10. 

Average  length  about  "48  mm. 
„         breadth    .,      "32     „ 

I  have  a  specimen  or  two  found  in  cellars  at  Mortlake,  Surrey, 
and  at  Tamworth,  which  strongly  resemble  Koch's  Opina  jiiteiis, 
but  it  is  difiicult  to  say  for  certain,  as  his  description  is  so  slight ; 
but  rather  than  make  a  new  species  I  adopt  his. 

Colour  brown ;  cephalothorax  about  half  the  length  of  the 
abdomen,  conical  about  two-thirds  of  its  length  (from  the  front) 
then  widening  sharply  to  a  slight  shoulder,  which  is  indented  for 
the  insertion  of  the  first  pair  of  legs,  but  forms  an  irregular  pro- 
jection extending  from  these  to  the  insertion  of  the  second  pair ; 
stigmatic  tubes  more  widely  separated  and  less  raised  than  usual  in 


British  Oribatidse.     By  A.  D.  Michael.  247 

genus.  A  long  hair  standing  upright  midway  between  each 
stigmatic  tube  and  the  central  line,  two  further  forward,  and  t;jvo 
short  curved  ones  at  the  point  of  the  rostrum.  Abdomen  oval, 
slightly  pointed  posteriorly,  very  polished,  two  rows  of  long  light 
hairs  round  margin,  two  separate  ones  in  the  centre  of  the  back 
(transversely),  near  the  anus,  and  four  shorter  round  the  anal 
margin ;  coxae  of  first  two  pairs  of  legs  concealed  from  above,  those 
of  two  posterior  pairs  conspicuous ;  legs  with  the  femoral  joints 
very  short  and  cylindrical,  other  joints  as  in  geniculatus ;  a  few 
light  hairs  on  each  joint. 

Dam/eus  splendens.     Koch. 

35.  Ojpjpia  sjjJendens.     Koch,  fasc.  32,  pi.  6. 

Average  length  about  '31  mm. 
„        breadth    „      "14     „ 

I  am  not  able  to  see  any  sufficient  distinction  between  the 
genera  Damseus  and  Opjna,  and  therefore  I  have  not  adopted  the 
latter. 

Found  at  Wandsworth,  Epping  Forest,  and  near  Tamworth. 

This  is  the  smallest  member  of  the  Oribatidse  I  have  found  ; 
why  Koch  called  such  a  minute,  unobtrusive  creature  sjplendens 
I  cannot  explain,  unless  it  were  a  kind  of  grim  joke :  his  descriptions 
and  figure,  however,  leave  Httle  doubt  as  to  identification ;  indeed, 
the  very  small  size  and  the  singular  way  in  which  the  joints  of 
the  legs  are  enlarged  nearly  into  balls,  making  the  legs  under  a 
low  power  look  like  a  string  of  beads  loosely  strung,  distinguish  it 
at  once.  This  is  conspicuous  and  exceptional  at  the  insertion  of 
the  tarsi  in  the  first  two  pairs  of  legs.  Stigmatic  hairs  rather 
long,  with  a  flat,  fusiform,  pointed  club. 

GENUS  TEGEOCRANUS. 

36.  Tegeocranus  latus.     Koch.    PI.  IX.  Figs  1,  2,  and  3. 

Ce])heus  latus.    Koch,  fasc.  3,  pi.  11. 
Tugeocranus  cepheiforynis.     Nic.  465. 

Found  by  Mr.  George  at  Kirton  Lindsey  and  by  me  at  Epping 
Forest ;  not  uncommon. 

The  English  specimens  have  not  the  two  hairs  on  the  vertex 
figured  by  Nicolet,  and  they  have  two  pairs  of  hairs  in  front  of  the 
mouth  instead  of  one. 

I  have  retained  Koch's  name,  being  unable  to  see  why  Nicolet 
has  rechristened  this  and  bestowed  Koch's  name  on  a  dift'erent 
creature  (discovered  by  Nicolet). 

This  is  the  species  above  referred  to,  of  which  I  have  bred  the 
very  singular  larva  and  nymph,  neither  of  which  have,  I  believe, 


248  Transactions  of  the  Society. 

been  before  observed,  and  seen  the  latter  change  to  the  perfect 
form. 

Larva  a  flattened  elhpse,  truncated  anteriorly ;  dorsal  surface 
coarsely  reticulated,  with  a  round  0{)aque  central  spot.  From  the 
edge  of  the  body  project  ten  long,  clear,  stout  spines,  each  doubly 
curved,  so  as  to  approach  the  line  of  beauty  in  shape,  and  armed 
with  short  spikes  at  intervals.  Two  rows  of  four  similar  spines  on 
back. 

The  nymph  is  similar  in  shape,  but  the  form  of  the  ellipse 
becomes  broader  with  each  change  of  skin ;  it  does  not  lose  the 
whole  of  the  larval  skin,  but  carries  the  dorso-abdominal  portion  of 
that  and  of  its  own  cast  skins,  in  situ  on  the  back,  lying  flat,  and 
concentrically.  Texture  same  as  larva,  colour  a  trifle  darker  with 
each  change  of  skin.  From  the  edge  of  the  dorsal  skin  proceed 
sixteen  large  trifid,  or  quadruple,  somewhat  chitinous  projections, 
the  form  and  arrangement  of  which  will  be  best  understood  by 
reference  to  Plate  IX.  Fig.  2  ;  the  central  lobe  of  each  projection 
carries  a  spine  like  the  larval  one,  inserted  (in  appearance)  like  a 
bird's  quill;  the  small  pointed  portion  of  the  projection  which 
springs  from  the  base  of  this  sj^ine,  as  shown  in  the  figure,  is 
absent  in  some  specimens.  The  spines  and  projections  occurring 
on  each  skin  give  the  creature  an  effect  of  great  complication.  It 
lives  on  the  bark  of  old  trees,  under  moss,  and  keeps  flat  on  the 
wood,  thus  its  spines  must  form  an  efficient  protection. 

Tegeocranus  coriaceus.     Koch.      PL  XI.  Fig  1. 
37.   Carahodes  coriaceus.     Koch,  fasc.  3,  pi.  15. 
Average  length  about  •  62  mm. 
„        breadth    „      "4     „ 

Found  at  Epping  Forest. 

Opening  for  mouth  organs  almost  entirely  closed  by  labimn ; 
second  joint  of  palpus  only  slightly  thicker  than  third,  fifth  joint 
not  toothed ;  mandibles  short  and  strong.  Whole  creature  very 
black,  but  dark  red  brown  where  seen  by  transmitted  light  (as  in 
the  stigmata). 

Form  bhort  and  broad;  ceplialothorax  very  broad,  flat,  tri- 
angular, and  joined  to  abdomen  by  the  full  breadth  of  the  former ; 
median  part  (longitudinally)  depressed  and  lighter  in  colour; 
central  (also  longitudinally)  m  this  light  space  are  two  small  raised 
black  ridges,  so  close  together  as  to  appear  one ;  these  commence  in 
the  centre  of  the  cephalothorax  and  extend  back  to  near  the 
abdomen,  then  cease  abruptly.  Sides  of  cephalothorax  raised  along 
the  whole  length,  extending  laterally  into  broad,  horizontal 
expansions,  pointed  anteriorly,  broadest  posteriorly,  where  they 
turn  inwards  at  acute  angles,  become  more  raised,  as  though  turned 
on  edge,  and  follow  the  curve  of  the  abdomen ;  before  reaching  the 


British  Orihatidx.     By  A.  I).  Michael.  249 

median  line  they  expand  into  rounded  lumps,  which  are  the  most 
raised,  and  then  become  narrower  and  turn  back  to  meet  the  lateral 
expansions :  between  the  two  lumps  and  opposite  the  termination 
of  the  first-named  ridges  is  a  narrow  depression,  not  quite  down  to 
the  level  of  the  cephalothorax ;  this  communicates  with  a  deep  and 
wide  depressed  channel  between  cephalothorax  and  abdomen :  from 
near  the  ends  of  this  channel  proceeds  a  smaller  one  which  runs 
round  the  abdomen.  There  is  a  raised,  rough,  exterior  margin, 
which  is  prolonged  into  small  angular  corners  ;  within  this  channel 
the  abdomen  is  almost  circular,  and  much  raised  and  marked  like 
morocco  leather,  whence  doubtless  Koch's  name.  Stigmata  large, 
raised,  and  pointed  outward,  stigmatic  hairs  curved  forward  and 
thickened  towards  the  ends;  two  rows  of  about  four  rather 
spatulate  white  hairs  on  the  back,  and  some  shorter,  projecting 
from  posterior  margin.  First  pair  of  legs  inserted  in  a  deej)  cleft 
of  cephalothorax,  which  is  open  above  and  below ;  second  pair 
supported  by  a  projecting  plate.  All  trochanters,  but  particularly 
first  pair,  very  thin  where  inserted,  and  greatly  and  suddenly 
thickened  towards  the  middle. 

Lives  chiefly  in  fungi  growing  on  old  trees. 

38.  Tegeocranus  labyrinthicus.    Mihi,  PL  XL  Fig.  2. 

Average  length  about  *  45  mm. 
„       breadth     „     '25  mm. 

New  Sjyecies. 

Found  by  Mr.  George  at  Kirton  Lindsey,  and  by  me  at  Epping 
Forest  and  near  Tamworth. 

A  small  species,  of  a  deep  red  brown  colour,  the  whole  creature 
covered  with  raised  dots,  close  together  and  often  coalescing, 
arranged  in  winding  lines  leaving  narrow  depressions  between. 

Cephalothorax  triangular,  broad,  and  joined  by  its  whole  width 
to  the  abdomen.  Along  whole  length  of  cephalothorax  runs  a  broad, 
free,  raised,  reticulated  expansion,  about  equal  in  width  until  near 
its  anterior  point,  but  having  a  semilunar  depression  in  the  margin 
near  where  it  joins  the  abdomen.  Stigmatic  hairs  with  thin  stalks 
and  piriform,  clubbed  ends.  First  and  second  pairs  of  legs  set  in 
shallow  clefts  of  cephalothorax;  all  trochanters  enlarged  beyond 
the  middle.  The  abdomen  has  the  sides  almost  parallel,  hind 
margin  rounded,  anterior  ditto  truncated  and  only  slightly  curved. 
The  border  usually  found  round  the  abdomen  in  this  genus  is 
wanting  or  rudimentary,  but  the  anterior  angles  are  expanded 
adjoining  the  cephalothorax.  A  row  of  short,  straight  hau's  round 
the  hind  margin. 

I  believe  this  species  to  be  unrecorded,  and  propose  to  call  it 
labyrinthicus,  from  the  maze-like  arrangement  of  the  rows  of  dots 
on  the  back. 


250  Transactions  of  the  Society. 

39.  Tegeocranus  elongatus.     Mihi,  PI.  X.  Fig.  7. 

Average  length  about  •  68  mm. 

„       breadth    „      •  32    „  at  broadest  part  of  abdomen. 
„  „        '2    „   where   abdomen   joins   cephalo- 

thorax. 
New  Species. 

Colour  black ;  whole  creature  from  point  of  rostrum  to  anus  a 
very  long  piriform  shape,  broadest  near  posterior  end,  which  is 
rounded,  the  line  of  the  cephalothorax  running  continuously  with 
the  abdomen  in  shape,  but  the  wings  of  the  cephalothorax  standing 
beyond  the  line. 

Cephalothorax  long,  a  third  of  the  length  of  the  whole 
creature,  conical,  nearly  flat,  sides  raised  into  projecting  wings, 
almost  horizontal.  Anterior  surface  of  the  vertex  covered  with 
slightly  raised  irregular  ridges.  Stigmata  at  the  extreme  edge  and 
posterior  limit  of  cephalothorax.  Stigmatic  hairs  short,  slightly 
curved  back,  gradually  thickened  towards  the  end,  which  is  rather 
bilobed.  Hairs  of  the  vertex  very  long,  almost  reaching  the  point 
of  the  rostrum ;  a  hair  from  beyond  the  middle  of  each  wing-like 
ridge  curved  over  the  rostrum,  the  two  crossing  ;  two  shorter  hairs 
near  point  of  rostrum  curving  downwards.  Last  two  joints  of  the 
legs  slighter  than  usual  in  the  genus.  Abdomen  coarsely  reticulated, 
nearly  straight  anteriorly,  with  two  small,  projecting,  blunt  points; 
border  of  abdomen  narrow  and  with  rough  edge,  four  lines  of  long 
hairs  down  its  dorsal  surface,  and  a  line  of  strongly  recurved 
shorter  ones  round  the  edge.  On  the  ventral  surface,  below  the 
wing-like  edges,  is  seen,  on  each  side,  a  shorter  similar  ridge,  reti- 
culated, and  armed  with  three  curved  teeth  on  the  anterior  edge. 
Genital  plates  much  rounded. 

This  creature  is  exceptional  amongst  the  Tegeocrani  from  its 
lengthened  form,  otherwise  it  presents  all  characteristics  of  the 
genus. 

I  beheve  it  to  be  unrecorded,  and  propose  to  call  it  Tegeocranus 
elongatus. 

It  lives  in  dead  wood  and  is  very  sluggish. 

GENUS  HERMANNIA. 
40.  Heemannia  piceus.     Koch. 
Nothrus  inceiis.     Koch,  fasc.  29,  pi.  2. 
Hermannia  crassipes.     Nic.  469. 
Murray. 
(?)  Hermannia  reticulata.    Thorell,  loc.  cit.    Nymph. 
Found  everywhere.     Common. 

Thorell's  description  of  his  reticulata,  found  at  Bell  Sound, 
appears  to  correspond  with  the  adult  nymph  of  this  species. 


British  Oribatidse.    By  A.  D.  Michael  251 

41.  Hermannia  arrecta,    Nic. 
Nic.  470. 
Found  Ly  Mr.  George  at  Kirton  Lindsey,  and  by  me  at  Epping 
Forest.     Not  uncommon. 

GENUS  HOPLOPHOKA. 

42.    HOPLOPHORA   MAGNA.      Nic. 

Nic.  472. 
Found  by  Mr.  George  at  Kirton  Lindsey,  and  by  me  at  Epping 
Forest  and  Loch  Maree.     Not  uncommon  in  dead  wood. 

43.  HoPLOPHORA   STRICULA.      Koch. 

Koch,  fasc.  2,  pi.  10. 
Nic.  472. 
Found  at  Kirton  Lindsey  by  Mr.  George,  and  by  me  at  Epping 
Forest. 

44.  HoPLOPHORA  DASTPUS.    Duges. 

Oribata  dasypus.    Duges,  '  Memoire  sur  I'ordre  des  Acariens,'  47. 
Hoplovliora  contradills.     Clap., '  Studien  an  Acariden.' 

„        _      Murray,  222. 
Phthiracarus  contractilis.     Perty. 
Soploiiiliora  nitens.     Langle  (unpublished). 
Nic.  423. 
Common  everywhere  in  dead  wood, 

I  do  not  see  why  Duges'  name,  which  seems  to  be  the  earliest, 
has  been  abandoned ;  I  have  therefore  used  it. 


252  Transactions  of  the  Society. 

XIII. — Notes  on  the  PygicVa  and  Cerci  of  Insects. 
By  Henry  Davis,  F.B.M.S. 

QRead  IZ'Ji  November,  1878.) 

Some  years  ago  most  microscopists  quoted  the  pygidium  of  a  flea 
as  being  one  of  the  best  of  definition  tests,  and  although  doubtless 
it  is  now  well  known  as  being  so  variable,  that  for  comparative 
trials  (where  objectives  are  not  tested  on  the  same  specimen)  it  is 
practically  of  little  value;  still  its  delicate  beauty,  the  puzzle  as 
to  its  function,  and  the  fact  of  its  being  generally  considered  as  an 
organ  unique  amongst  insects,  keep  it  to  the  present  day  as  an 
object  of  abiding  interest,  and  one  without  which  no  cabinet  would 
be  called  complete. 

As  one  of  its  early  admirers,  I  gave  it,  some  years  ago,  con- 
siderable attention,  and  was  able  not  only  to  convince  myself  that 
the  angular,  square-shouldered  outline  of  the  rays  in  the  areola, 
thus  figured  in  the  '  Micrographic  Dictionary,'  has  no  foundation  in 
fact,  but  that  those  areolae  possess  some  outer  structure  which 
seems  hitherto  to  have  escaped  notice.  It  has  afforded  me  a  some- 
what malicious  pleasure  in  chaUeuging  those  of  my  friends  who 
used  high  modern  powers,  to  discover  this  structure  for  themselves. 
They  invariably  failed.  A  small-angled  ^-inch  objective,  fully  twenty 
years  old,  first  showed  that,  looking  on  an  areola  as  representing  a 
carriage  wheel,  a  line  proceeds  outwards  from  the  tire  between 
each  spoke,  and  these  lines  being  bounded  by  a  circle,  give  resem- 
blance to  a  wheel  within  a  wheel :  the  new  wheel  or  circular  band 
is,  when  the  object  is  unflattened  by  pressure,  at  right .  angles  to 
the  plane  of  the  inner  wheel;  the  first  forming  the  sides,  and 
the  latter  the  bottom  of  a  Httle  pit,  from  the  centre  of  which 
springs  the  well-known  fine  long  hair. 

This  is  not  brought  forward  for  the  purpose  of  glorifying  old 
objectives,  or  decrying  the  power,  optical  and  manipulatory,  of 
certain  microscopists,  but  rather  to  show  the  advantage  of  mounting 
one's  own  preparations ;  for  the  structure  can  only  be  well  made  out 
when  the  object  is  placed  in  a  position  which  a  professional  mounter 
would  endeavour  to  avoid  and  consider  as  wrong  side  out. 

Until  1870,  when  Mr.  Peake  discovered  a  pair  of  pygidia  on 
the  Lace- wing  fly  [Ghrysopa  jpeola),  the  Flea  appears  to  have  been 
the  only  insect  known  to  possess  this  appendage,  and,  after  dihgent 
inquiry,  I  cannot  find  that  since  that  date  any  published  addition 
has  been  made  to  the  number.  But  in  December,  1870,  it  was  my 
fortune  to  notice  two  pygidia  on  a  fine  Locust  (Locusta  migratoria) 
I  had  captured  near  Cadiz,  and  after  finding  these  the  road  was 
made  to  very  many  discoveries  in  other,  mostly  allied,  insects.     It 


On  the  Pijgiclia  and  Cerci  of  Insects.     By  Henry  Davis.  253 

will  be  a  safe,  because  an  under,  statement  to  say,  that  without  any- 
special  search,  fifty  insects  of  different  species  are  now  proved  to 
possess  pygidia.  The  organ  is  here  spoken  of  in  the  plural,  as 
with  the  single  exception  furnished  by  Piilex,  all  the  insects 
examined  have  it  in  pairs  more  or  less  sej)arated ;  even  in  the  Flea 
it  is  distinctly  double  and  bilateral,  and  I  submit  it  should  no 
longer  receive  the  singular  appellation  except  when  divided. 

It  would  doubtless  be  satisfactory  to  give  a  full  Hst  of  all  the 
insects  on  which  I  have  found  pygidia,  but  it  happens  that  by  far 
the  greater  number  are  exotic,  taken,  some  at  the  Cape  of  Grood 
Hope,  some  in  Mauritius,  and  other  places  abroad ;  the  correct 
naming  is  a  difficult  task ;  even  Mr.  Frederick  Smith  of  the  British 
Museum  shrank  from  it,  and  I  am  constrained  to  speak  of  the 
foreign  species  in  general  terms,  but  will  give  particular  examples 
in  common  English  insects. 

The  pygidia  of  the  Lace- wing  may  be  taken  first,  as  introductory 
to  a  series  gradually  increasing  in  size ;  they  are  found  as  nearly 
circular,  flat,  or  slightly  convex  plates,  one  on  each  side  of  the  last 
(posterior)  joint  of  the  abdomen ;  they  are  dorsal,  and  only  require 
to  be  pushed  (so  to  speak)  closer  together  to  be  exact  copies  of  the 
pygidia  of  the  Flea.  It  has  a  similar  collection  of  the  same  shaped 
areolae  and  the  same  characteristic  fine  long  central  hair.  Next  to 
this,  as  having  pygidia  of  the  nearest  resemblance  to  that  of  the 
Lace- wing,  comes  the  common  small  Grasshopper  {Gryllus) ;  in  this 
the  organs  project  slightly,  conical  in  figure  and  somewhat  flattened 
at  the  sides,  but  otherwise  they  are  exactly  similar  to  the  only 
pygidia  hitherto  known.  In  the  large  Grrasshopper  {Acrida  viri- 
dissima)  the  parts  are  much  longer  and  not  easily  overlooked, 
while  in  the  Cricket  {Acheta  domestica)  we  find  these  same  organs 
extended  to  an  immense  length — sometimes  three-quarters  of  an 
inch — but  still  bearing  the  peculiar  structure  of  rayed  and  haired 
areolae.  The  Mole  Cricket  {Gryllotalpa  vulgaris)  also  has  large  and 
■beautifully  marked  pygidia. 

In  the  Cock-roach  {Blaita  orientalis)  may  be  found  correspond- 
ing large  appendages,  which  are  called  cerci  by  Burmeister ;  except 
in  position,  there  is  little  at  a  glance  to  identify  them  with  the 
parts  we  have  seen.  They  are  nearly  bare  on  the  superior  surface, 
and  t]ie  under  side,  often  turned  upwards  and  outwards,  only  is 
furnished  with  any  long  hairs;  nor  are  these  set  in  broad,  deep 
sockets  like  those  described,  but  are  attached  to  small,  clear,  unrayed 
spaces,  flush  with  the  chitinous  integument.  To  found  a  belief  that 
these  cerci  are  really  pygidia,  it  requires  considerable  acquaintance 
with  the  latter's  various  modifications,  and,  above  all.  a  knowledge 
of  the  very  peculiar  properties  of  the  long  hairs  to  be  mentioned 
presently. 

Of  foreign  insects  having  pygidia,  I  purpose   saying  little, 


254  Transactions  of  the  Society. 

although  they  have  supphed  the  greatest  number  and  variety  of 
examples.  Among  these  it  really  would  seem  as  if  all  the  ortho- 
pterous  insects  have  them,  and  most  of  the  Neuroptera.  Some  are 
very  minute,  even  when  the  owner  is  of  large  size  ;  others  greatly 
elongated,  as  in  Lucina  opilioides,  where  the  organ  is  over  an  inch 
long.  Curious  instances  may  be  found  in  Thuxalis,  in  Heterodes ; 
also  in  an  Indian  Grasshopper  (possibly  anonymous),  which  has  the 
organ  twisted,  and  tipped  with  a  hard  serrated  hook. 

As  regards  the  function  of  pygidia,  it  might  appear,  at  first 
sight,  that  the  new  examples  being  mostly  of  large  size,  there 
would  be  little  difficulty  in  investigating  and  determining  a  matter 
which,  in  the  case  of  Pulex,  has  vainly  taxed  the  skill,  patience,  and 
acumen  of  many  excellent  observers ;  and  probably  if  the  subject 
were  taken  up  again  by  biologists  well  versed  in  the  anatomy  and 
physiology  of  insects,  satisfactory  results  might  accrue ;  but  as  a 
matter  of  fact,  the  inquiry  is  by  no  means  an  easy  one,  and  after 
considerable  study  of  fine  and  various  specimens,  I,  for  a  long  time, 
only  arrived  at  a  conclusion — an  old  one,  it  would  seem,  of  the  late 
Mr.  llichard  Beck — that  pygidia  are  collections  of  tactile  hairs 
forming  posterior  feelers ;  but  quite  lately,  almost  by  an  accident, 
I  was  enabled  to  see  that,  while  they  may  be  this,  they  certainly 
are  something,  and  very  much,  more. 

I  had  a  pygidium  of  a  Cricket  under  a  low  power,and  was  surprised 
to  see  a  strong,  waving  motion  in  the  hairs ;  this,  at  first,  was  attri- 
buted to  action  imparted  at  the  will  of  the  insect,  although  it  was 
at  the  time  stupefied  and  quieted  with  chloroform ;  but  the  same  sort 
of  movement  occurred  when  the  creature  was  quite  dead,  and  when 
only  a  thin  section  of  the  organ  was  under  the  Microscope.  It  was 
found  that  the  hairs  are  so  light  and  so  delicately  attached,  that  the 
ordinary  breathing  of  the  observer,  at  fully  ten  inches  distance,  set 
them  in  motion ;  and  a  slight  movement  of  the  hand  a  foot  or  more 
away  caused  a  visible  disturbance,  which  is  not  a  mere  vibration, 
but  a  rocking  of  the  motile  hair  in  its  socket,  and  of  the  disk  by 
which  it  is  attached.  In  repeating  this  exj)eriment,  it  is  necessary 
to  examine  the  part  within  a  short  time  of  the  death  of  the  insect, 
and  before  the  rigor  mortis  has  set  in ;  otherwise  the  little  disk  at 
the  base  of  the  hair  (sometimes  there  is  a  rounded  end,  but  never 
a  root)  will  become  more  or  less  firmly  fastened  to  the  white 
(nervous  ?)  matter  in  which  it  seems  set,  and  the  hair  will  be  found 
comparatively  insensitive. 

It  will  be  seen  that  as  mere  tactile  hairs  they  are  far  too 
delicate  ;  moreover,  examples  may  be  found  in  some  species  of 
Lace-wing,  and  notably  in  the  Flea  of  the  Pigeon,  where  by  being 
surrounded  by  coarse  true  hairs,  or  placed  under  stout  curved 
spines,  they  are  partly  or  wholly  protected  from  contact  with 
external  bodies.     I  am  led  to  believe  pygidia  to  be  collections  of 


On  the  Pygidia  and  Cerci  of  Insects.     By  Henry  Davis.     '255 

motile  hairs,  forming  organs  of  feeling  induced  by  the  move- 
ment of  the  air  in  their  neighbourhood ;  not,  perhaps,  an  organ 
of  a  new  sense  between  touch  and  hearing,  but  of  feeling  not 
excited  in  the  ordinary  way  by  actual  touch.  I  apprehend  that  any 
insect  having  pygidia  must  infallibly  be  warned  of  the  approach, 
however  stealthy,  of  an  enemy ;  even  if,  from  its  position  behind 
the  insect,  that  enemy  could  not  be  seen,  the  warning  being  given 
by  the  moving  hairs  actuated  by  the  disturbance  of  the  surrounding 
air. 

In  these  notes  I  think  may  be  found  reasons  for  discarding  the 
use  of  the  word  "  cerci,"  as  applied  to  all  those  insect  organs  which 
are  plainly  modified  forms  of  the  better  known  "pygidia."  The 
latter  simply  meaning  something  on  the  iiropigium,  will  permit  them 
to  be  of  any  form  or  size ;  and  as  ''  cerci "  means  tails,  it  is  absurd 
to  apply  it  to  objects  of  no  length,  as  the  pygidia  of  Chrysopa 
and  Pulex.   But  if  these  be  tails,  then  indeed  man  himself  has  one. 


25G  Transactions  of  the  Society. 

XIV. — On  Stephenson  s  System  of  Homogeneous  Immersion  for 
Microscope  Objectives.* 

By  Professor  E.  Abbe,  of  Jena,  Hon.F.E.^I.S. 

{Read  12th  March,  1879.) 

The  inventor  of  the  Immersion  method,  Amici,  with  whose  name  so 
many  important  improvements  in  the  IMicroscope  are  connected, 
attempted  to  use  other  fluids  than  water  for  the  immersion  medium. 
Amongst  others  he  tried  the  highly  refractive  oil  of  aniseed,  pro- 
bably from  the  idea  that  the  advantage  obtained  by  replacing  the 
stratum  of  air  by  a  more  refractive  medium  would  increase  with  the 
increase  in  the  refractive  indices  of  the  media  employed.  More 
recently  others  have  used  glycerine,  and  the  well-known  American 
optician  Spencer  has,  according  to  report,  produced  objectives  by 
this  means  of  excellent  quality. 

The  theoretical  analysis  of  the  immersion  principle  shows,  that 
in  several  respects  far  more  favourable  results  can  be  attained  with 
a  highly  refracting  substance  than  with  water :  it  proves,  however, 
at  the  same  time,  that  the  advantage  to  be  expected  is  by  no  means 
proportional  with  the  progressive  increase  in  the  refractive  index; 
on  the  contrary,  there  is  a  maximum  beyond  which  the  results 
become  less  favourable.  When  the  cover-glass  and  the  front  lens 
are  of  crown-glass,  which  is  generally  the  case,  this  maximum 
is  reached  when  the  immersion  fluid  has  the  same  refractive  index 
as  crown  glass.  A  connection,  which  is  optically  homogeneous,  is 
then  established  between  the  preparation  and  the  objective,  which 
eliminates  all  refraction  in  front  of  the  first  spherical  surface  of  the 
optical  system.  Not  only  is  the  loss  of  light  by  reflection  obviated, 
a  loss  which  is  experienced  at  every  surface  separating  different 
optical  media  when  the  incident  rays  are  oblique,  but  what  is  still 
more  important,  a  very  considerable  amount  of  spherical  aberration 
is  at  the  same  time  prevented  which  otherwise  would  have  to  be 
corrected  in  the  upper  portion  of  the  objective,  but  which  must 
leave  a  residuum.  Apart  therefore  from  other  advantages,  such 
a  method  of  "  homogeneous  immersion  "  gives  promise  at  all  events 
of  a  more  perfect  elimination  of  spherical  aberration,  and  conse- 
quently more  favourable  conditions  for  what  is  called  "  definition  "  of 
the  objective,  than  water  immersion.  It  also  possesses  the  further 
advantage,  which  is  by  no  means  inconsiderable,  of  getting  rid  of 
the  disturbing  influence  of  the  cover-glass  and  doing  away  entirely 
with  the  otherwise  indispensable  correction.  For  where  the  inter- 
vening medium  is  equal  in  its  refraction  and  dispersion  to  the 
cover-glass,  it  is  immaterial,  as  regards  the  optical  effect,  whether  a 
*  Translated  by  E.  Woodall,  Esq.,  F.R.M.S. 


System  of  Homogeneous  Immersion.     By  Prof.  E.  Abbe.     257 

thicker  layer  of  glass  and  a  corresponding  thinner  layer  of  the  fluid, 
or  vice  versa,  is  inserted  between  the  object  and  the  objective. 

The  idea  of  realizing  the  various  advantages  of  such  a  kind  of 
immersion,  by  constructing  objectives  on  this  system,  had  for  some 
time  presented  itself  to  my  mind,  but  I  thought  that  there  was  not 
much  to  be  expected,  as  regards  the  scientific  usefulness  of  such 
objectives,  as  I  believed  their  use  would  be  limited  on  account  of 
the  necessity  of  using  oil  or  some  other  inconvenient  material 
as  the  immersion  fluid.  It  appeared  to  me  that,  except  perhaps 
for  the  examination  of  diatoms,  scarcely  any  other  scientific  sphere 
remained  than  petrographic  research,  which  would  afibrd  scope  for 
realizing  the  optical  advantages  of  such  objectives. 

The  matter  assumed,  however,  subsequently  a  different  shape 
in  consequence  of  a  suggestion  made  by  Mr.  John  Ware  Stephenson 
(the  Treasurer  of  the  Eoyal  Microscopical  Society  of  London),  who 
independently  discovered  the  principle  of  Homogeneous  Immersion,* 
but  by  whom,  in  addition  to  its  other  advantages,  special  attention 
was  drawn  to  the  doing  away  with  the  cover-glass  correction,  and 
to  the  possible  enlargement  of  the  angular  aperture,  with  conse- 
quent increase  in  the  resolving  power  of  the  objective.  This  idea 
of  Mr.  Stephenson,  which  made  the  matter  one  of  universal  scien- 
tific interest,  was  at  once  followed  out,  the  calculations  being  made 
by  me,  and  the  technical  execution  by  Mr.  Zeiss,  and  resulted  in 
the  production  of  a  series  of  objectives  on  this  system  which  in 
several  respects  are  manifestly  superior  to  the  ordinary  water-im- 
mersion objectives.  Having  now  been  used  by  a  number  of  micro- 
scopists,  it  has  been  found,  that  although  the  nature  of  the  peculiar 
immersion  fluid  will  naturally  much  restrict  the  employment  of 
such  objectives,  it  does  not  present  any  obstacle  to  their  use  in 
various  widely  different  spheres  of  microscopic  research ;  and  in 
particular,  biology  furnishes  many  problems  to  which  the  new 
lenses  may  render  useful  service. 

Since  the  construction,  about  a  year  ago,  of  the  first  objectives 
on  this  system,  the  focus  being  ^"  nominal  (more  exactly  2  ■  6  mm. 
equivalent  focus),  and  all  of  them  calculated  for  the  long  tubes  of 
the  English  Microscopes,  some  have  been  made  of  y^"  (1  '8  mm.), 
which  give  suflScient  magnifying  power,  even  with  the  shorter 
tubes  of  the  continental  instruments ;  and  quite  recently  a  third 
series,  i\"  nominal  (1"2  mm.  focus)  has  been  produced,  by  which, 
especially  in  histological  observations,  great  amplification  can  be 
obtained  with  low  eye-pieces. 

The  angular  aperture  of  all  these  objectives  is  about  114°  in 
the  immersion  fluid  for  which  they  are  adapted,  the  index  of  refrac- 
tion being  taken  in  round  numbers  as  :=  1  '50. 

*  J.   W.   Stephenson   "  On   a  Large-angled    Immersion    Objective    ^vitilout 
Adjustment  Collar,"  &c. — This  journal,  i.  (1878)  51. 

VOL.   II.  S 


258  Transactions  of  the  Society. 

This  is  approximately  the  same  angular  magnitude  as  can  be 
attained  without  any  great  difficulty  within  the  film  of  water  in  the 
usual  immersion  lenses,  or  within  the  stratum  of  air  in  dry  objec- 
tives. But  since  the  "  numerical "  equivalent  of  the  angle  of  aperture 
(the  measure  which  determines  the  number  of  rays  taken  in  by  the 
objective)  is  proportional  not  only  to  the  sine  of  half  the  angle  of 
aperture,  but  also  to  the  refractive  indices  of  the  respective  media 
employed,  and  since  all  the  functions  of  the  angle  of  aperture,  and 
especially  the  resolving  power  of  the  Microscope,  are  regulated  by 
this  numerical  equivalent,  it  follows  that,  according  to  theory,  the 
capacity  of  the  new  objective,  compared  with  that  of  ordinary  im- 
mersion lenses,  is  increased  in  the  proportion  of  1  •  50  to  1  •  33,  and 
as  compared  with  the  highest  dry  objectives,  as  1  '50  to  1. 

The  product  of  the  sine  of  half  the  angle  of  aperture  into  the 
refractive  index  of  the  medium — the  '•  numerical  aperture,"  as  I 
call  it — reaches  1  •  25  to  1  •  27  in  these  objectives.  The  ratio  of 
these  figures  to  unity  expresses  how  much  greater  is  the  number 
of  rays  admitted  by  the  new  objectives,  over  that  number  which  in 
air  would  fill  a  complete  hemisphere,  or  which  would  be  admitted 
by  an  imaginary  dry  objective  of  180°  aperture. 

This  unusually  large  aperture  is  accompanied  with  a  notable 
increase  of  resolving  power.  This  is  at  once  evident  by  the  facility 
with  which  very  fine  striae  and  similar  markings  become  visible  on 
the  more  difficult  test  objects ;  by  the  plainness  with  which  the 
characteristic  markings  stand  out  on  the  more  complicated  forms, 
such  as  Frustiilia  saxonica,  Surirella  gemma,  &c. ;  and  lastly,  by 
several  unusual  features  which  appear  when  certain  methods  of 
illumination  are  employed  on  the  coarser  tests  of  this  kind,  e.  g. 
P.  angidatum. 

Histological  preparations  also  furnish  instances  of  very  small 
elements  closely  clustered  together,  granulations  and  such  like, 
in  which  clearer  and  more  definite  resolution  is  obtained  in  critical 
cases. 

At  the  same  time,  in  all  these  objects,  especially  in  those  last 
named,  the  decidedly  more  perfect  definition  which  homogeneous 
immersion  renders  possible,  is  obtained,  provided  that  the  precision 
of  the  technical  execution  is  adequate  to  the  reduction  efi'ected  in 
the  residual  aberration  as  indicated  in  theory.  Therefore,  when 
comparatively  strong  eye-pieces  are  used  the  image  retains  great 
sharpness,  so  that  in  regular  work  higher  amplification  can  be  use- 
fully employed  than  is  usually  the  case  with  other  objectives  of 
equal  focal  length.  They  also  often  enable  more  exact  observations 
to  be  made  of  very  delicate  objects,  such  as  fine  cilia,  than  good 
immersion  objectives  of  the  ordinary  kind  would  permit. 

Lastly,  as  a  proof  of  excellence  of  definition  which,  though 
indirect,  is  of  special  weight,  may  be  mentioned  the  favourable 


System  of  Homogeneous  Immersion.     By  Prof.  E.  Ahhe.     2o9 

results  which  Dr.  Koch,  of  Wollstein,  obtained  when  examining 
bacteria,*  viz,  by  employing  a  full  cone  of  rays  filhng  the  entire 
aperture  of  the  objective,  a  method  of  illumination  quite  unheard 
of  as  applied  to  such  objects  and  with  such  an  angular  aperture. 
With  this  illumination,  which  can  only  be  eflfected  by  the  aid 
of  a  condenser  of  large  aperture,  the  preparation  is  simultaneously 
penetrated  in  all  directions  by  the  incident  rays.  As  a  result, 
the  .  delineation  of  such  parts  as  stand  out  in  mutual  contrast 
through  difference  in  refractive  power  (tissue  structures,  &c,),  is 
almost  completely  suppressed,  and  there  remain  visible  only  those 
elements  which  act  as  absorbents  through  staining.  On  the  other 
hand,  the  essential  advantages  of  oblique  illumination  are  retained, 
although  the  illumination  remains  central  in  name,  in  consequence 
of  the  co-operation  of  the  rays  incident  at  a  large  angle  towards 
the  axis  of  the  Microscope,  Very  small  and  closely  clustered 
elements,  as  in  prejDarations  of  bacteria,  must  certainly  on  both 
these  accounts  become  capable  of  a  more  thorough  resolution  than 
with  central  illumination  of  the  usual  kind ;  if,  however,  this 
ingenious  method  of  observation  is  to  show  corresponding  results, 
the  defining  properties  of  the  objective  must  stand  a  most  severe 
test,  and  this  test  will  be  the  more  severe  in  proportion  to  the 
magnitude  of  the  angular  aperture  employed. 

As  regards  the  nature  of  the  immersion  fluid,  it  is  of  course  on 
optical  grounds  a  matter  of  indifference  what  is  selected,  so  long 
only  as  it  is  homogeneous  and  transparent,  and  equal,  or  very  nearly 
equal,  to  crown  glass  in  refraction  and  dispersion.  Experiment  has 
taught,  however,  that  this  condition  of  homogeneous  immersion 
leaves  a  much  smaller  choice  than  might  be  anticipated.  At  the 
outset  I  examined  over  one  hundred  fluids  of  the  most  varied  kinds — 
essential  and  fatty  oils  and  artificial  chemical  preparations— which 
I  either  tested  myself  or  caused  to  be  examined  with  the  refracto- 
meter,  to  determine  their  refractive  and  dispersive  indices,  and 
lately  the  investigation  has  been  carried  still  further  by  Dr,  'J'opel, 
who,  under  my  guidance,  determined  the  optical  constants  of  nearly 
two  hundred  chemical  combinations  from  the  collection  in  the 
laboratory  of  the  Jena  University,  which  Professor  Geuther  was 
kind  enough  to  place  at  our  disposal.  Among  all  these,  however, 
not  one  was  found  which  from  its  other  properties  could  be  used ; 
which  either  alone  or  mixed  with  other  fluids  attained  the  refractive 
index  of  crown  glass  (1'515  to  1-520  for  sodium  hght)  without  at 
the  same  time  more  or  less  exceeding  the  disjiersion  of  crown  glass, 
A  few  only  of  the  substances  examined  satisfied  the  necessary 
conditions  with  sufl&cient  accuracy  to  permit  the  deviation  to  be 
regarded  as  unimportant. 

The  most  suitable  fluid  that  has  at  present  been  discovered,  is 

*  '  Aetiologic  del- AVundinfektions-Kriiiikheiten.'     Leipsic,  1871). 

s  2 


260  Transactions  of  the  Sociefy. 

cedar- wood  oil  (prepared  by  Scliimmel  and  Co.,  Leipsic  and  New 
York)  an  essential  oil  almost  without  colour  or  smell,  and  not 
volatile,  but  unfortunately  rather  thin.  Its  refractive  index  at  a 
medium  temperature  is  about  1"51,  whilst  the  dispersion  only 
slightly  exceeds  that  of  crown  glass.  The  objectives  have  therefore 
been  constructed  for  use  with  this  oil. 

For  a  more  extended  application  of  the  principle  of  homogeneous 
immersion  great  advantage  is  derived  from  the  fact,  that  by  mixing 
one  of  the  more  highly  refracting  essential  oils,  such  as  oil  of  cloves, 
fennel,  aniseed,  or  others,  with  a  certain  quantity  of  olive  oil, 
fluids  can  be  readily  obtained  which  are  equal  to  cedar- wood  oil 
in  refractive  power,  but  whose  dispersive  power  may  be  increased 
more  or  less,  as  required.  This  provides  a  means  of  regulating  the 
chromatic  correction  of  greater  delicacy  than  is  attainable  by  any 
mere  mechanical  correction,  inasmuch  as  for  cedar- wood  oil  can  be 
substituted  mixtures  of  various  dispersive  power,  according  to  the 
nature  of  the  object  to  be  examined  and  the  kind  of  illumination 
required.  By  this  simple  means,  for  example,  the  chromatic 
difference  of  spherical  aberration,  a  correction -de  feet  which  (in  the 
present  state  of  practical  optics)  it  is  impossible  to  overcome  in 
objectives  of  large  aperture,  is  rendered  for  the  most  part  immaterial. 
This  unavoidable  defect  is  apparent  from  the  fact  that  the  central 
and  peripheral  zones  of  the  objective  are  never  simultaneously 
perfectly  achromatic.  An  objective  which  with  oblique  light  gives 
an  image  as  free  from  colour  as  possible,  is  found,  when  central 
illumination  is  used,  to  be  chromatically  under- corrected  to  a  marked 
degree,  in  the  case  of  a  sensitive  object,  and  conversely.  This  is  the 
more  striking  the  larger  the  angular  aperture.  If,  now,  instead  of 
a  stratum  (with  parallel  surfaces)  placed  in  the  course  of  the  rays 
we  substitute  another  of  equal  refractive  but  different  dispersive 
power,  we  obtain  a  simple  means  of  changing  the  chromatic  cor- 
rection of  the  objective  without  altering  the  spherical  correction, 
and  if,  as  is  done  throughout  in  the  construction  of  these  lenses, 
the  chromatic  compensation  is  so  arranged  that  the  fluid  having 
the  lowest  dispersion  (cedar-wood  oil)  produces  the  best  achroma- 
tism for  oblique  light,  the  use  of  a  more  highly  dispersive  mixture 
of  the  kind  mentioned  will  correct  the  chromatic  defect  for  central 
illumination  which  would  otherwise  appear. 

The  application  of  this  method  is  adversely  affected  by  one 
circumstance  only,  viz.,  that  the  effect  of  a  determinate  increase  in 
the  dispersion  naturally  depends  upon  the  thickness  of  the  fluid 
stratum.  With  covering  glasses  of  different  thickness,  as  also 
with  objectives  of  different  focal  lengths  and  corresponding  different 
working  distances,  one  and  the  same  mixture  will  yield  more  or  less 
unequal  results. 

Since  the  exact  adjustment  of  the  immersion  fluid  thus  appears 


Si/siem  of  Homogeneous  Immersion.     By  Prof.  E.  Abbe.    261 

essentially  necessary  if  the  capacity  of  the  new  objectives  is  to  be 
fully  utilized,  it  is  important  to  have  a  simple  means  of  regulating 
the  refractive  and  disjDersive  powers  of  the  fluids  in  their  relation  to 
the  corresponding  factors  in  crown  glass  without  having  to  employ 
special  measuring  apparatus.  For  this  purpose  Mr.  Zeiss  furnishes 
with  each  objective  a  small  glass  bottle  with  parallel  sides,  to  the 
glass  stopper  of  which  is  cemented  a  crown  glass  equilateral  prism. 
This  test  bottle  may  be  used  in  preparing  the  combined  fluids, 
and  by  viewing  the  vertical  bar  of  a  window  frame,  &c.,  through 
both  fluid  and  prism  the  difierence  between  the  fluid  and  crown 
glass,  both  with  respect  to  refraction  and  dispersion,  may  be  at 
once  seen.  The  deflection  of  the  image  of  the  vertical  bar  in 
passing  through  the  prism,  and  the  width  of  the  coloured  border, 
gives  both  these  elements  at  a  glance  and  with  an  exactness  which 
is  quite  sufficient. 

In  the  practical  use  of  the  new  objective  there  are  two  further 
points  to  be  specially  noticed.  The  first  is  its  dependence  upon  the 
length  of  the  tube.  The  abolition  of  the  cover-glass  correction  in 
these  objectives,  which  is  acknowledged  by  all  observers  to  be  an 
extraordinary  advantage  in  manipulating  the  lenses  with  ease  and 
certainty,  nevertheless  deprives  the  observer  of  a  convenient  means 
of  compensating  within  certain  limits  the  influence  of  diflerent  tube- 
lengths  upon  the  aberrations.* 

The  objectives  can  therefore  only  be  used  with  the  length  of 
tube  for  which  they  are  originally  adjusted,  and  they  are  so  sensi- 
tive on  this  point  (especially  the  lowest  power)  in  consequence  of 
the  large  angular  aperture,  that  a  deviation  of  a  very  few  centi- 
metres in  the  length  of  the  tube  produces  visible  changes  in  the 
condition  of  the  correction.  A  draw  tube  to  the  Microscope  affords 
therefore  a  very  simple  means  of  regulating  according  to  the 
observer's  own  judgment,  the  ultimate  more  delicate  adjustment 
of  the  correction,  and  also  enables  him — until  some  better  immer- 
sion fluid  is  found — to  compensate  any  small  defect  in  the  refraction 
of  cedar- wood  oil,  which  may  be  noticeable  when  very  thick  or  very 
thin  cover-glasses  are  used.  (As  lengthening  the  tube  produces 
spherical  over-correction,  and  shortening  under-correction,  it  follows 
that  the  former  corrects  a  very  thin  covering  glass,  and.  the  latter 
one  of  more  than  ordinary  thickness.) 

*  Dispensing  with  the  correction-adjustment  in  the  manufacture  of  sucli  objec- 
tives is  a  matter  of  small  moment  in  itself  when  compared  with  the  other  technical 
requirements  which  are  met  by  it.  An  essential  benefit  arises,  however,  from 
the  simplification  of  the  mechanical  construction,  in  so  far  as  it  would  scarcely 
be  possible  in  a  combination  of  lenses  with  movable  parts  to  get  the  lenses  centered 
as  perfectly  and  durably  as  is  possible  in  the  case  of  a  fixed  combination  :  and  in 
the  present  instance  this  appears  an  iadispensable  condition  on  account  of  the 
sensitiveness  of  the  large  aperture  to  the  slightest  defect  in  centering.  Looking 
at  tiiis  circumstance,  it  would  be  most  unadvisablc  to  provide  such  objeotives  with 
correction  collars. 


202  Transactions  of  the  Society. 

In  using  the  objectives  for  photograpliy,  where  the  image  must 
be  at  a  considerable  distance,  unless  an  ordinary  low  eye-piece  is 
used  to  photograph  with,  an  auxiliary  lens  becomes  requisite,  which 
will  remove  the  image  to  the  required  distance,  without  altering 
the  course  of  the  rays  in  the  objective  itself.  For  this  purpose 
a  concave  lens  of  suitable  focal  length  may  be  inserted  close  behind 
the  objective  in  the  same  way  as  a  short-sighted  person  uses  concave 
spectacles  to  move  the  plane  of  distinct  vision  to  a  greater  distance ; 
a  concave  lens  of  relatively  corresponding  shorter  focal  length  may 
also  be  interposed  at  a  greater  distance  from  the  objective,  in  order 
to  produce  a  moderate  amplification  (two  or  three  times)  of  the  image, 
and  at  the  same  time  a  decrease  in  the  requisite  distance  of  the 
plate.  The  position  of  the  auxiliary  lens  in  this  case  must  of  course 
be  so  regulated,  by  computation,  that  the  cones  of  rays  emerging 
from  the  objective  converge  towards  the  same  j)lane  as  in  ordinary 
observation. 

A  second  point  which  must  not  be  lost  sight  of  in  using  these 
objectives— and  in  fact  any  objective  the  numerical  aperture  of 
which  considerably  exceeds  the  value  1 — relates  to  the  conditions 
which  the  illuminating  apj)aratus  must  satisfy,  in  order  that  the 
whole  angular  aperture  may  be  utilized  with  oblique  illumination. 

With  a  numerical  aperture  of  1  •  25  an  incident  ray,  if  it  is  to 
reach  the  external  zone  of  the  objective,  must,  when  it  impinges  on 
the  object,  be  incident  towards  the  axis  of  the  Microscope  at  an 
angle  of  about  56°.  Eays  with  this  inclination  cannot  of  course 
be  transmitted  to  the  objective  out  of  air  through  a  flat  surface 
perpendicular  to  the  axis,  such  as  the  lower  surface  of  the  glass 
slide.  An  incident  ray  reaching  this  surface  from  below  would  not, 
after  entering  the  glass,  be  inclined  towards  the  axis  more  than 
about  42° ;  and  with  the  ordinary  illuminating  mirror  even  this 
obliquity  could  never  be  attained,  apart  from  the  great  loss  of  light 
by  reflection,  which  would  greatly  detract  from  the  effect.  In 
order  therefore  to  utilize  the  maximum  degree  of  oblique  illumina- 
tion, which  an  objective  of  such  large  aperture  will  admit — of 
course  with  objects  which  do  not  lie  in  air — and  to  bring  out  the 
full  defining  power  of  the  objective,  an  illuminating  apparatus  is 
necessary,  which  not  only  gives  a  cone  of  rays  of  equal  aperture 
with  the  objective,  but  which  at  the  same  time  admits  of  a  fluid 
connection  with  the  under  side  of  the  slide.  One  immersion  c in- 
denser  amongst  others  which  fulfils  these  conditions,  is  the  illumi- 
nating apparatus  described  by  me  *  some  years  ago,  the  system  of 
lenses  in  which  (corresponding  with  the  angle  of  aperture  of  the  older 
immersion  objectives  of  Zeiss)  possesses  a  "  numerical  aperture  "  of 
over  1  •  1  for  its  upper  focus,  and  in  the  construction  of  which  the 
*  Max  Schultzc's  '  Aicliiv  f.  IMikr.  Anat.,'  ix.  496. 


System  of  Homogeneous  Immersion.     By  Prof.  E.  Abbe.    263 

connection  of  the  front  lens  with  the  under  surface  of  the  shde  by 
a  drop  of  water,  is  taken  into  account.*  In  the  absence  however 
of  an  ilhiminating  apparatus  such  as  this,  and  where  only  very 
oblique  ilium inatiou  is  required,  a  much  more  simple  arrangement 
will  be  found  very  serviceable,  which  consists  in  connecting,  by 
means  of  a  drop  of  glycerine  or  oil,  a  plano-convex  lens,  nearly 
hemispherical,  of  6-9  mm.  radius,  to  the  under  surface  of  the  slide, 
to  which  it  will  adhere.  It  may  be  kept  sufficiently  centered  by 
means  of  a  loose  brass  ring  attached  to  it,  having  an  external 
diameter  equal  to  that  of  the  stage  aperture.  The  ordinary 
concave  mirror,  turned  slightly  outside  the  axis  of  the  Microscope, 
will  then  give  cones  of  rays  of  any  degree  of  obliquity  which  may 
be  desired. 

In  conclusion,  some  account  may  be  given  of  the  optical  com- 
binations of  the  objectives  for  homogeneous  immersion.  Those 
constructed  in  Mr.  Zeiss'  manufactory,  and  based  upon  my  com- 
putations, are  all  systems  with  four  members.  In  this  1  have 
gone  back  to  a  type  of  construction  which  was  applied  by  me 
experimentally  many  years  ago,  and  has  lately  been  used  with 
considerable  success  by  several  opticians,  especially  Mr.  Tolles  and 
Mr.  Spencer.  Two  single  crown-glass  lenses  close  together  are 
made  use  of  (duplex  front)  as  the  lower  members  of  the  system, 
and  the  two  others  only  are  compound,  so-called  achromatic  (in 
the  present  case  binary)  lenses. 

This  form  has  certainly  the  disadvantage  of  leaving  rather  more 
chromatic  difference  of  the  magnifying  power  (that  is,  with  perfect 
achromatism  in  the  middle  of  the  field  of  view  there  is  more  colour 
towards  the  periphery)  than  is  usually  found  when  the  front  lens  of 
the  system  is  followed  immediately  by  a  compound  lens  of  flint  and 
crown  glass ;  but  this  defect  is  practically  inconsiderable  in  com- 
parison with  the  facility  with  which  it  enables  the  angle  of  aperture 
to  be  increased.  The  form  in  which  1  have  devised  this  type  is 
nevertheless  essentially  diflerent  from  the  construction  of  which 
Mr.  Tolles  has  published  the  elements  in  detail. f  The  difference 
becomes  very  ap})arent  when  the  radii  of  the  front  lenses  are  compared 
with  the  equivalent  focal  distances  of  the  respective  objectives. 
The  \"  objective  of  Tolles,  described  in  the  journal  referred  to,  hag 
almost  exactly  4  mm.  focal  length,  and  its  front  lens  a  radius  of 
0  •  73  mm.  In  Zeiss's  ^Vj  with  1  •  8  mm.  of  focal  length — con- 
sequently less  than  half — the  radius  of  the  front  lens  is  no  less  than 

*  In  consequence  of  the  greater  aperture  of  the  objectives  for  homogeneous 
immersion,  I  have  recently  had  a  system  of  lenses  constructed  for  an  illuminatino- 
apparatus,  the  angular  nperture  of  which  reaches  approximately  the  numerical 
equivalent  1*4.  This  will  consequently  give  rays  which  are  inclined  72°  towards 
the  axis  in  glass. 

t  This  Journal,  i.  (1S78)  143 


2(j4  Transactions  of  the  Soeietrj. 

0  '9  mm.,  and  even  with  the  y'^"  (1  '2  mm.  focal  length)  the  smallest 
radius  (O'O  mm.)  is  very  httle  less  than  that  of  Tolles's  ^",  whilst 
an  objective  of  equal  power  would  require,  according  to  Tolles's 
formula,  the  abnormally  small  radius  of  0 "  22  mm. 

For  the  advantageous  application  of  the  duplex  front  in  ob- 
taining larger  angular  aperture,  the  more  favourable  ratio  between 
the  radius  of  the  front  lens  and  the  focal  length  which  is  here 
attained  will  be  of  some  importance,  because  it  provides  the  only 
possible  means  of  producing  objectives  of  great  magnifying  power, 
without  having  too  much  recourse  to  the  tube  and  eye-j)iece  for 
amplification.  By  Tolles's  construction  it  would  be  practically 
impossible  to  make  an  objective  such  as  Zeiss's  xV">  ^ot  to  mention 
the  ~i\",  with  an  angle  of  aperture  of  any  considerable  extent,  to 
say  nothing  of  the  intolerable  limitation  of  the  working  distance  of 
lenses  so  abnormally  small. 

As  far  as  the  mere  observation  of  diatoms  and  similar  test- 
objects  is  concerned,  an  objective  of  4  mm.,  if  thoroughly  well  made 
and  possessing  a  good  large  angle  of  aperture,  would  indeed  leave 
scarcely  anything  to  be  desired,  especially  as  the  small  front  lens  of 
Tolles's  consl  ruction  involves  relatively  favourable  conditions  for 
the  employment  of  deep  eye-pieces.  But  when  we  take  into  con- 
sideration the  much  more  complicated  structures  of  the  difficult 
objects  of  biological  research,  it  cannot  be  doubted  that  systems 
which  give  considerably  higher  objective  amplification  will  remain 
a  real  necessity  until  in  practical  optics  more  perfect  methods  of 
getting  rid  of  the  aberration  than  at  present  known  are  discovered. 
In  my  opinion,  therefore,  looking  to  general  scientific  requirements, 
the  end  to  be  kej)t  in  view  at  present  is  the  production  of  objectives 
of  sufficiently  short  focal  length,  which  do  not  present  too  much 
difficulty  in  ordinary  use,  and  this  has  been  the  principle  which 
has  guided  me  in  my  labours  in  this  particular  case. 

A  decidedly  unfavourable  feature  in  the  formula  which  I  have 
produced  is  the  technical  difficulty  of  construction,  in  which  require- 
ments are  made  such  as  were  scarcely  ever  demanded  and  satisfied 
in  the  manufacture  of  Microscopes.  In  this  construction  the 
spherical  surface  of  the  front  lens  must  be  utilized  to  an  extreme 
extent,  and  must  bear  angles  of  incidence  which  for  the  marginal 
rays  (on  the  air  side)  exceed  45°.  The  manufacturing  optician 
has  therefore  to  produce  spherical  surfaces  of  the  small  dimensions 
of  the  front  lens,  which  shall  be  strictly  true  in  form  to  the  extent 
of  a  full  hemisphere,  and  afterwards  to  mount  these  lenses  in  such 
a  manner  that  without  affecting  tiie  firmness  of  their  setting  they 
shall  freely  admit  rays  of  light  nearly  up  to  the  equator.  The 
difficulty  of  this  work  and  the  extreme  sensitiveness  to  the  least 
defect  of  form  and  centering  of  the  lenses,  in  a  system  of  so  great 
an  angular  aperture,  make  the  production  of  such  objectives  an 


System  of  Homogeneous  Immersion.   By  Prof.  E.  Abhe.    265 

exceptionally  troublesome  and  delicate  task.  All  these  difficulties 
of  technical  execution  would,  however,  be  considerably  diminished 
if  the  increase  in  the  angular  aperture  were  to  some  extent  sacri- 
ficed and  we  were  content  with  a  numerical  aperture  of  1 '  to  1  •  1, 
which  has  hitherto  been  the  ordinary  aperture  of  immersion  lenses. 

I  must  for  the  present  leave  undecided  the  question  whether 
the  Stephenson  immersion  system  might  not  prove  of  great 
practical  service  even  under  such  restrictions.  Of  course  such 
advantages  would  be  surrendered  as  arise  from  the  augmented 
resolving  power,  since  this  is  essentially  determined  by  the  magni- 
tude of  the  aperture.  But  there  are  surely  objects  enough  in  the 
domain  of  the  microscopist,  with  respect  to  which  a  specially  high 
resolving  power  is  of  less  moment  than  the  greatest  possible  per- 
i'ection  of  definition ;  and  the  superiority  of  the  homogeneous 
immersion  system  on  this  point,  and  the  great  advantage  which  the 
elimination  of  the  disturbing  effect  of  the  cover -glass  involves, 
would  be  diminished  only  to  a  very  limited  extent  with  a  reduced 
angle  of  aperture.  Assuming,  therefore,  that  the  nature  of  the  im- 
mersion fluid  admits  the  frequent  use  of  such  lenses,  especially  in 
biological  researches,  it  might  be  desirable  to  try  the  system  of 
homogeneous  immersion  in  objectives  of  more  simple  construction, 
which  would  by  their  smaller  cost  be  more  generally  used. 

In  the  other  direction,  however,  the  extent  to  which  the  new 
immersion  method  will  lead  us  has  been  by  no  means  exhausted  by 
the  new  objectives.  From  the  result  of  the  first  step  it  cannot  be 
doubted  but  that  by  this  system  considerably  larger  apertures  of 
moderately  short  focal  length  are  still  attainable,  notwithstanding 
the  increasing  difficulties  of  computation  and  construction.  It 
being  unquestionably  a  matter  of  interest  to  extend  the  resolving 
power  of  the  instrument  to  its  extreme  limits  by  any  means  in  our 
power,  even  if  the  unavoidable  refinements  in  such  objectives 
scarcely  admit  of  their  frequent  application,  the  attempt  has  been 
undertaken  in  the  optical  manufactory  here.  I  hope  soon  to  be 
able  to  show  objectives  of  4-3  millimetres  focal  length,  the  nu- 
merical aperture  of  which  is  increased  to  1  •  35,  corresponding  to  an 
aperture  angle  of  128°  in  a  medium  with  an  index  of  1  "50.  This 
figure,  however,  would  be  the  extreme  limit  which  can  at  present  be 
attained,  unless  cover-glasses  of  flint  glass  are  used  for  the  object, 
and  at  the  same  time  an  immersion  fluid  of  corresponding  refrac- 
tive index  is  applied. 


2()6  Transactions  of  the  Society. 

XV. — The  Vertical   Illuminator    and   Homogeneous   Immersion 
Objectives.    By  J.  W.  Stephenson,  F.E.A.S.,  Treas.  E.M.S. 

(Head  9th  April,  1879.) 

The  Fellows  will  have  seen  in  the  April  number  of  the  Journal 
(p.  194)  a  note  extracted  from  the  'American  Naturalist'  for 
February,  in  which  are  described  the  advantages  found  by  Mr. 
Morehouse,  of  New  York,  to  be  obtained  from  the  use  of  the  Vertical 
Illuminator  *  in  the  resolution  of  Diatoms  and  Podura  scales. 

On  reading  the  note,  I  tried  the  apparatus  on  both  classes  of 
objects,  and  can  fully  endorse  the  statement  made  as  to  the  sur- 
prising results  obtained.  Slides  of  A.  ])ellucida  which  were 
deemed  worthless  because  all  the  striae  had,  as  was  supposed,  been 
destroyed  in  cleaning,  were  resolved  with  the  greatest  ease,  and 
Podura  showed  parallel  light  or  white  lines  from  one  end  of  the  scale 
to  the  other,  somewhat  reminding  one  of  Lepisma.  The  Vertical 
Illuminator  was  soon  after  its  first  invention  discarded  by  practical 
microscopists  on  account  of  the  amount  of  fog  which  was  caused 
by  the  reflection,  at  the  upper  surface  of  the  cover-glass,  of  the 
rays  transmitted  through  the  objective.  It  is  obvious  that  this  fog 
will  not  be  observed  when  an  oil-immersion  objective  is  used,  as  in 
that  case  the  front  lens  of  the  objective,  the  intervening  stratum 
of  oil,  and  the  cover-glass  itself,  are  all  optically  continuous,  so 
that  the  upper  surface  of  the  cover-glass  has  optically  ceased  to 
exist,  the  only  reflection  being  from  its  under  surface  when  dry 
objects  are  used.  An  additional  advantage  is  therefore  found  for 
homogeneous-immersion  objectives. 

My  object  is  not,  however,  to  deal  with  this  branch  of  the 
subject,  but  with  an  entirely  diflerent  application  of  the  Illuminator, 
not  noticed  by  Mr.  Morehouse,  but  which  appears  to  me  to  be  of 
great  scientific  interest. 

This  point  is  the  visible  demonstration  which  the  Vertical 
Illuminator  affords,  not  only  that  many  modern  objectives,  and 
notably  those  on  the  homogeneous-immersion  system,  have  angles 
far  exceeding  the  equivalent  angle  of  180°,  but  also  that  the 
extent  to  which  this  excess  is  in  any  particular  case  carried,  can 
at  once  be  appreciated. 

The  existence  of  this  excess,  although  at  one  time  doubted,  has 

*  As  several  inquiries  have  been  made  as  to  what  instrument  is  meant  by  the 
"  Vertical  Illuminator,"  I  may  refer  to  Dr.  Carpenter  '  On  the  Microscope,'  5th  erl., 
p.  153,  where  the  instrument  is  both  described  and  figured.  A  small  silver 
speculum  (Professor  Smith),  or  a  movable  disk  of  thin  glass  (Messrs.  Beck),  or  a 
piece  of  parallel  glass  fixed  at  an  angle  of  45°  (Messrs.  Powell  and  Lealand),  is 
fixed  in  a  short  tube  (with  a  side  aperture)  interposed  between  the  objective 
and  tlie  body  of  the  INIicroscope,  by  which  means  a  pencil  of  light  entering  at  the 
aperture  and  striking  against  the  spccuhnn  or  inclined  surface  of  the  disk  or  plate, 
is  reflected  downwards  through  the  objective  ujjon  the  object. 


The  Vertical  Illuminator,  &c.    By  J.  W.  Stephenson.     267 

since  been  abundantly  proved,  and  the  present  method  affords  an 
ocular  demonstration  of  the  fact,  most  conclusive  in  its  character 
and  fully  supported  by  theory. 

It  will  be  seen,  on  removing  the  eye-piece  of  the  Microscope, 
after  having  reflected  a  full  beam  of  light  through  the  objective,  by 
means  of  the  Illuminator,  and  after  having  focussed  the  instrument 
on  any  dry  object  adhering  to  the  cover,  that  within  the  margin  of 
the  lens  there  exists  a  brilliant  annulus  of  light,  and  that  the  circum- 
scribed internal  space  appears  by  comparison  to  be  quite  dark. 

This  annulus  rej)resents,  and  is  produced  by,  the  excess  of 
aperture  beyond  the  equivalent  angle  of  180  ,  or  what  is  called  the 
"  plus  1(:>0^,"  of  which  it  is  also  the  measure. 

The  internal  dark  space  is  of  the  exact  diameter  of  that  of  a 
dry  objective  of  the  same  focus,  and  is  in  fact  the  maximum  space 
which  it  can  itself  utilize,  on  a  dry  object,  by  transmitted  light. 

On  looking  down  the  tube  of  the  Microscope  on  which  is  one  of 
Zeiss's  homogeneous-immersion  iths,  with  its  numerical  aperture  of 
1  •  25,  it  will  be  seen  that  the  annulus  has  an  apparent  magnitude 
corresponding  with  that  attributed  to  it  by  theory,  that  is  to  say,  a 
width  equal  to  one-fourth  part  of  the  radius  of  the  dark  central  space. 

The  explanation  is.  as  it  appears  to  me,  simple  enough  :  the 
beam  of  light  reflected  by  the  parallel  glass  plate  of  the  Illuminator, 
is  condensed  by  the  objective,  and  brought  to  a  focus  on  the  under 
side  of  the  thin  glass  cover,  the  oil  (or  other  homogeneous  fluid) 
having,  thus  far,  allowed  the  light  to  be  freely  transmitted ;  but,  at 
the  focal  point,  having  to  pass  from  a  denser  to  a  rarer  medium, 
the  passage  of  all  rays  which  exceed  the  critical  angle  (in  this  case 
41  )  is  arrested,  whilst  those  within  that  limit,  or  at  all  events  the 
greater  part  of  them,  pass  through  the  glass  and  are  lost. 

The  bright  image  of  the  flame  of  the  lamp,  which  is  seen 
crossing  the  field  of  view,  is  therefore  almost  exclusively  formed  by 
the  "j;/t<s"  rays,  which,  being  totally  reflected  as  soon  as  they 
impinge  on  the  air  surface  of  the  cover-glass,  are  sent  back  by 
the  peripheral  portion  of  the  objective  to  the  eye ;  it  is  thus  evident 
that,  unless  the  objective  possessed  the  excess  of  aperture  which  we 
have  been  considering,  the  image  could  not  be  formed  by  the  totally 
reflected  rays,  nor,  if  formed,  could  the  reflected  rays  be  taken  up 
by  the  objective  and  transmitted  to  the  eye. 

These  reflected  rays,  when  seen  without  the  eye-piece,  form  the 
bright  annulus  of  light,  and  constitute,  as  has  been  sljown,  the 
aperture  in  excess  of  the  180°  limit,  which  limit  is  itself  as  clearly 
indicated  by  the  dark  central  area. 

That  this  is  not  a  mere  theoretical  or  nominal  increase  is 
evident  when  we  consider  the  areas  of  the  transmitting  portions  of 
the  lens,  which  are  proportional  to  the  squares  of  their  numerical 
apertures  or  as  1  to  1 '  5625,  so  that  the  Vertical  Illuminator  })icks 


268  Transactions  of  the  Society. 

up  the  0'5625  as  against  unity,  wtich  is  the  ideal  maximum  of 
the  dry  lens. 

It  is  truly  stated  in  the  'American  Naturalist'  that  the  Vertical 
Illuminator  "  can  only  he  successfully  used  in  conjunction  with  an 
objective  of  high  balsam  angle,"  and  I  hope  the  reason  of  this  has 
been  rendered  clear. 

In  examining  a  dry  object  with  reflected  and  transmitted  light, 
the  optical  phenomena  are  reversed :  with  reflected  light  we  have 
the  bright  annulus  and  dark  centre ;  but,  with  light  transmitted 
from  below,  we  have  the  central  portion  of  the  lens  traversed  by 
the  illuminating  pencil,  which  is,  however,  unable  to  penetrate  the 
dark  circle  by  which  it  is  surrounded. 

On  objects  mounted  in  balsam  (or  fluid)  the  Vertical  Illuminator 
fails,  as  far  as  resolution  is  concerned,  and  it  is  on  these  that  the 
various  sub -stage  immersion  illuminators  come  into  play,  their 
greater  or  less  success  depending  exclusively  on  their  ability  to 
induce  the  dioptric  beam  to  penetrate  the  magic  circle  beyond  the 
limit  of  180^,  as  unless  the  light  can  be  seen  to  touch  the  margin 
of  the  lens,  its  full  power  has  not  been  developed  ;  hence  it  appears 
that  "  vertical "  illumination,  in  some  form,  is  the  only  means  by 
which  the  whole  of  the  resolving  power  of  large-angled  objectives 
can  be  utihzed  on  dry  slides,  just  as  on  balsam  objects  immersion 
illuminators  are  indispensable. 

In  the  foregoing  observations  I  have  throughout  spoken  of  the 
bright  riiig  of  light,  and  this  may  lead  to  the  impression  that  the 
whole  of  this  ring  is  used,  but  this  is  not  so ;  in  practice  only  a 
small  portion  is  employed,  the  greater  part  being  shut  off  by 
a  suitable  external  diaphragm  or  stop,  just  as  with  immersion 
illuminators  in  the  sub-stage  a  part  only  of  the  marginal  rays  are 
employed. 

This  seems  to  suggest  the  substitution  of  a  small  totally  re- 
flecting prism  for  the  parallel  plate  of  glass,  which,  projecting 
slightly  over  the  margin  of  the  lens,  gives  a  much  more  brilliant 
beam  of  light,  but  it  has  the  disadvantage  of,  to  a  certain  extent, 
interfering  with  the  diffraction  spectra,  and  thus  under  some 
circumstances,  so  diminishing  the  aperture  of  the  glass,  as  to 
interfere  with  its  resolving  power. 

The  Vertical  Illuminator  was  originally  intended  to  be  used 
more  as  a  Lieberkuhn  for  opaque  illumination  with  medium  powers, 
its  present  use  not  having  been  foreseen.  That  it  can  be  so  used 
with  even  greater  efi'ect  on  balsamed  objects  now,  when  homo- 
geneous immersion  objectives  are  used,  is  obvious,  because  the  light 
passes  as  direct  as  it  formerly  did  on  to  uncovered  objects  in  air, 
both  the  upper  and  under  surfaces  of  the  thin  glass  cover  having  been 
optically  abolished — but  the  number  of  balsam  objects  suitable  for 
opaque  illumination  with  powers  as  high  as  an  g,  is  very  hmited. 


(     269     ) 

XVI. — Note  on  Diagrams  {Plate  XII.)  exhibiting  the  Path 
of  a  Bag  through  Tolles  \  Immersion  Objective. 

By  Professor  R.  Keith. 

{Read  9th  April,  1879.) 

I  HAVE  sent  with  this  note  additional  diagrams  (Plate  XII.)  to 
aid  in  localizing  the  symbols  and  following  out  the  formulae  used 
in  the  computation  of  the  ^  immersion  objective  made  by  Mr. 
R,  B.  Tolles  and  owned  by  Mr.  Crisp.*  The  lines  are  not  drawn 
to  any  scale,  although  the  elements  of  the  objective  are  entered 
upon  the  lines  corresponding  to  those  in  the  objective  itself. 

It  will  be  observed  that  the  ray  of  light  finally  emerges  from 
the  plane  surface  of  the  small  lens  without  refraction.  It  is,  of 
course,  supposed  to  enter  material  of  the  same  refractive  power  as 
the  lens  itself:  meeting  the  point  in  discussion  upheld  by  Mr. 
Wenham,  viz.  that  there  is  some  interior  impossibility  of  using 
more  than  82^  of  aperture  in  balsam.  It  will  be  further  observed 
that  the  ray  meets  the  plane  surface  at  an  angle  of  over  55^,  and 
therefore  if  that  surface  divides  the  glass  from  air,  it  cannot  pass 
out  of  the  lens ;  since  at  41°  and  upwards  the  effect  of  the  great 
difi'erence  of  density  between  glass  and  air  is  to  stop  the  light.  It 
is  thus  seen  that  the  limit  of  aperture  in  air  does  not  indicate  the 
limit  of  aperture  in  any  denser  material,  the  limiting  angle  being 
greater  the  denser  the  material ;  being  90^  when  the  densities  are 
equal. 

*  See  vol.  i.  Plate  VII.  Professor  Keith  notifies  the  following  errata  in  the 
lithographed  computation : — 

In  the  elements  furnished  by  Mr.  Tolles,  r  —  0  •  29  shoidd  be  »•  —  0  •  029,  and 
in  the  fourth  column  of  figures,  seventeenth  line  from  the  top,  55°  5'  51"  should 
be  55°  5'  21". 


270  Transactions  of  the  Socieiy. 


XVII.  —Note  on  Mr.  Wenham's  paper  "  On  the  Measurement  of  the 
Angle  of  Aperture  of  Objectives."     By  Professor  K,  Keith. 

(Read  12th  Fehruary,  1879.) 

Mr.  Wenham,  in  a  paper  read  November,  1878,*  seems  to  appre- 
hend the  interference  of  outside  light  in  the  ordinary  process  of 
measuring  angular  aperture,  but  his  attempt  to  explain  this 
interference  fails  to  show  where  his  difficulty  is.  His  figure  has  no 
meaning  in  connection  with  the  subject,  as  the  outside  legs  of  the 
tripod  will  not  after  refraction  come  to  the  same  point  in  the  field 
of  the  Microscope  that  the  central  one  does,  and  therefore  have 
nothing  to  do  with  the  measurement.  They  will,  of  course,  after 
refraction  fall  far  to  the  right  and  left  of  the  centre,  and  have 
nothing  to  do  with  the  aperture  question.  One  point  in  the  image 
corresponding  to  one  point  in  the  object,  and  one  only,  is  to  be 
considered  in  making  the  measurement  for  aperture.  It  is  true 
that  with  the  sector  as  ordinarily  used,  first  one  edge  of  a  lamp 
flame  is  brought  to  the  centre  of  the  field,  and  then  the  other  edge : 
but  the  few  minutes  of  arc  subtended  by  the  flame  are,  strictly,  to 
be  subtracted  from  the  reading  of  the  sector,  thus  practically 
making  one  edge  of  the  flame  only  the  object  of  consideration. 

Those  interested  will  bear  in  mind  that  in  measuring  aper- 
ture with  the  sector,  the  lamp  flame  is  placed  far  enough  away 
to  render  the  rays  of  light  sensibly  parallel.  The  Microscope  tube 
is  then  inclined  to  the  direction  of  the  lamp  flame,  until  the  outside 
ray  of  the  flame  is  bent  along  the  axis  to  the  centre  of  the  field,  and 
the  sector  read.  The  tube  is  then  again  inclined  to  the  direction 
of  the  flame  on  the  opposite  side  until  the  outside  ray  of  the  flame 
is  again  bent  along  the  axis  to  the  centre  of  the  field,  and  the  sector 
again  read. 

Half  the  difference  of  the  readings  gives  practically  the  exact 
amount  by  which  the  ray  of  light  is  bent.  The  whole  difference  is 
under  these  circumstances  the  angular  aperture,  and  if  two  lights 
be  placed  so  that  their  directions  will  form  that  angle  at  the 
objective,  both  lights  will  be  visible  at  the  same  time  in  the  Micro- 
scope. Whether  the  lights  give  but  a  single  ray  or  a  large  bundle 
of  parallel  rays,  the  result  will  be  the  same.  Any  allusion  to 
outside  rays  as  interfering  in   this   simple   process  is   therefore 

erroneous. 

*  Vol.  i.  p.  321. 


(     271     ) 

XYIII. — Reply  to  tlie  foregoing  Note. 
By  F.  H.  Wenham,  F.K.M.S. 

{Read  9th  April,  1879.) 

As  those  who  have  been  engaged  in  the  aperture  controversy  have 
explained  their  meaning  repeatedly,  I  quite  agree  with  ^Yhat  I 
understand  is  the  view  of  the  Council,  that  it  should  now  be 
closed  till  some  new  fact  appears  to  elucidate  the  question. 

Professor  Keith's  Note  does  not  call  for  discussion,  as  the  ob- 
jections appear  to  arise  from  a  misapprehension  of  the  acting 
conditions  of  the  sector  measurement.  The  flame  does  not  remain 
in  the  centre  of  the  field  of  the  eye-piece  during  the  traverse,  and 
there  is  no  axial  bisection ;  the  least  movement  sideways  causes  the 
image  of  the  lamp  to  leave  the  centre,  and  when  at  last  the  light 
margin  divides  the  field,  the  half  illumination  is  actually  caused 
from  the  eclipse  of  the  light  by  the  edge  of  the  eye-piece  stop. 
The  position  of  the  distant  flame  can  be  seen  with  an  '•  examining 
lens "  over  the  eye-piece.  The  field  is  traversed  by  the  beam  of 
light ;  this  successively  intersects  all  the  oblique  pencils  of  the 
object-glass  which  afterwards  enter  together  in  proximity  at  the 
eye-piece  at  a  very  small  angle  of  divergence. 

The  sector  measurement  fails  to  indicate  true  angles  of 
aperture,  and  in  order  to  prove  this  without  theorizing,  I  de- 
scribed in  my  last  paper  a  plain  and  unmistakable  demonstration. 
I  took  a  series  of  decisive  angles  of  aperture  by  the  ''  triangle " 
method,  viz.  from  the  focal  distance  up  to  a  definite  diameter  of 
front  lens ;  I  then  measured  the  angle  from  each  of  these  restricted 
diameters  or  apertures  by  the  sector,  employed  precisely  in  the 
ordinary  manner,  and  tabulated  the  comparative  results  as  "  false 
apertures." 

With  this  I  am  content  to  allow  all  personal  controversy  to 
remain  at  rest,  as  I  consider  that  I  have  clearly  proved  that  angle 
of  aperture  is  usually  measured  greatly  in  excess,  as  angle  of  field. 


(     272     ) 


NOTES  AND  MEMOKANDA. 


t^'  It  is  intended  in  future  niunbcrs  of  the  Journal  to  classify  the  Notes 
and  Memoranda  and  Bibliography  as  shown  below,*  by  whicli  plan  it  is  believed 
that  the  value  of  the  Journal  as  a  scientific  record  will  be  enhanced, 

ZOOLOGY. 

A.  GENERAL,  including  Embryology  and  Histology  of  the  Verte- 

BRATA. 

B.  INVERTEBRATA. 


>. 

/(a)  Protozoa. 

(6)   PORIFERA. 

"a 

>-, 

(c)  Ccelenterata. 

^ 

(rf)  Echinodermata. 

(c)  Vermes. 

If)  Arthuopoda. 

(a)  Crlstacea. 

(/3)  Arachnida. 

(7)  Myrtapoda. 

s 

\                  (5)    iNSECTA.f 

(7)   MOLLUSCOIDA. 

(h)  Mollusc  A. 

BOTANY. 

A.  GENERAL,  including  Embbtology  and  Histology  op  a  he  Phanero- 

GAMIA. 

B.  CRYPTOGAMIA. 

•  >.  f  C'^)  Alg^. 
•M'a     (^)  Lichenes. 
rS  "=  I  (c)  Fungi. 
^  J  \  (d)  Charace.^. 

o  §^     (e)  MusciNE/15. 
So  V(/)  Vascular  Cryptogams. 

MICROSCOPY. 

(Instrumental— Methods,  Reagents,  &c.) 

ZOOLOGY. 

A.  GENERAL,  INCLUDING  EMBRYOLOGY  AND  HISTOLOGY  OF 
THE  VERTEBRATA. 

Nuclei  of  the  Blood-corpuscles  of  the  Triton.  —  Urged  by  the 
publication  of  Strieker's  researches,  according  to  which  the  nuclei  of 

*  We  are  aware  that  this  classification  is  more  or  less  open  to  criticism,  but 
we  have  adopted  it  as  being  on  the  whole  the  most  convenient  for  this  particular 
purpose  at  least. 

T  It  is  not  proposed  to  deal  exhaustively  with  the  Insects ;  that  branch  of  the 
Animal  Kingdom  being  already  well  provided  both  with  journals  and  special 
societies. 


NOTES    AND    JlKMOn.VNIW.  27«^ 

the  corpuscles  are  not  constant  structiu\>s,  M.  l\>ncIiot  lias  made  son»i> 
observations,*  of  which  the  t'oHowinu;  are  the  cliict' conclusions  : 

(1)  The  red  and  wliite  corpusch>s  are  doriv»>d  rn)ni  the  sann>  ana- 
tomical elements.  ('2)  The  nuclei  of  the  white  corpusch>s  unihir^^o 
complete  segmentation,  hut  (J?)  this  scgn\entiilion  dot's  not  o(MMU'  so 
long  as  theyax'o  freely  suspended  and  moving  in  (lu>  scmmum.  (■{)  Th(^ 
rod  corpuscles  are  "  tinal  chMuentary  forms."  (5)  Tlie  so calh^l  roti- 
culum  in  these  corpnsi-les  of  the  Triton  is  mendy  tlie  n-sult  <d'  the 
partial  division  of  the  substance  of  the  nnch^us.  ((i)  In  dovoh>p- 
meut  these  nuclei  reach  a  cortiiin  maximum  size,  and  thou  (b>('rt>aH(>. 
(7)  The  red  blood-corpus(dcs  themselves  (lisiip|)rar  by  dissolution  iti 
the  serum.  (8)  There  is  no  iissiparous  muitiplienliion  of  r(>d  blood- 
corpuscles  aft(U"  that  tlies(^  bodi«is  become  provided  with  hiemoglobin, 
(9)  As  is  well  known,  the  red  corpuscles  may  b(^  discoid  or  ovoi<l 
in  shajHi,  rthI  it  is  suggestt^d  that  there  is  some  relation  bi'tweeii  tlieso 
two  forms  and  the  nu)lecular  state  of  tlio  contiined  luenioglobin.  Tlio 
nucleolus  of  the  corpuscdes  is  dciliiuid  as  being  that  point,  or  thoso 
points,  which  luivo  a  greater  "  (dcctivo  alii n i t.y  "  for  carmine.  Tho 
paper  is  illustrated  by  a  plate  of  sixteen  (igures. 

Division  of  Cartilage  Cells. —  An  importiuit  rcHeareh  on  this  Hubject 
is  publislKid  by  W.  ScbleiclKir,!  whose  results  agree  in  the  main  with 
those  of  Flenmiing.J  but  diller  in  many  points  not  wholly  iininiportiuit. 
Schleicher  denies  the  pr(!S(jn(;e  of  a  true  intranuclear  n(^t\vorl(,  bid/ 
describes  rods,  fd)res,  and  granules  (Stiibeheii,  If^iidchon,  tind  Korner), 
as  existing  witliin  the  nu(d(!us.  'j'h(i  lirst  step  in  tho  division  of 
a  cartilage  cell  consists  in  the  disintegration  of  the  niudear  irKimbrano  ; 
next,  the  contentsof  tin;  nucleus  the  rodH,(V:e.,unrl(!rgoan  extraonlinary 
series  of  changes  of  form  and  position,  the  whole  nueleiis  at  the  mimo 
time  constantly  changing  its  position.  After  a  time,  the  rods,  itc, 
take  on  a  more  or  less  [larnllel  arrangement,  and  then,  be(;oiriinf^ 
approximated  at  their  extremities,  form  a  more  or  b;sH  fuHilorm  figure, 
corresponding  to  the  spiiidle-nmdeiiH  of  other  observeiH.  The  approxi- 
mated ends  of  tho  rods  then  fuse  together,  and  division  tiiht'S  plaeo 
along  a  piano  taken  through  the  centre,  and  pe,ip(;ndiciilar  to  the  long 
axis  of  the  spindle.  'J'he  nuclei  of  the  two  daughter-eel  Is  are  tliiiM 
produced;  each  of  these  beeomr;s  resolved  int(»  rods  and  (ibrcH,  thoHO 
undergo  changes  of  form,  and,  at  length,  those  situated  towiudu  the 
peripliery  of  the  nucleus  curve  roiitifi  and  fuse  with  one  another, 
forming  a  new  nuclear  membrane.  In  the  membranebms  Ktato  of  tho 
nucleus  a  connection  was  observed  betw«;en  its  fibreft  and  thoKO 
occurring  in  the  protoplanm  of  tlie  e,ell  the  intriieelliilur  network 
of  other  authors.  Some  observatioriH  made  tended  to  tli<;  ojiinio/i  that 
the  intracellular  fibres  arone,  by  a  proecHS  of  de,|;i.ri]in;itio;i,  from  th<) 
capsule  of  the  cell. 

Influence  of  the  different  Colours  of  the  Spectrum  on  Animali,— 

The  article   of   M.    E.    Yung,  of   which    we    gave   an  abstract  (ffun 

*  Kobin'rt  '.Joiirn.  Au-'it.  <:t,  I'liyw.,'  xv.  (\HT.i)  '.>. 
+  '  Archiv.  f.  Mikr.  Anat..,'  xvi.  (\H1H)  2J.V 
X  Thi'..  Jonrn;.],  ii.  CIW^  K57. 
VOL.  II.  T 


274  NOTES  AND    MEMORANDA. 

•  Comptes  Rendus ')  at  p.  138,  lias  now  been  publislied  in  Professor 
Lacaze-Duthiers'  '  Archives,'*  wliere  it  occupies  thirty-two  pages. 

B.  INVEETEBRATA. 

Formation,  Fructification,  and  Division  of  the  Animal  Ovum. — 
This  subject  is  treated  of  in  two  papers  by  Oscar  Hertwig,f  each 
illustrated  by  three  plates.  He  works  out  very  fully  for  Echino- 
derms,  Worms,  Coelenterates  and  Molluscs,  the  important  questions  of 
the  fate  of  the  germinal  vesicle,  the  formation  of  the  "  polar  cells," 
the  precise  phenomena  attending  impregnation,  and  the  mode  of  forma- 
tion of  the  first  cleavage-nucleus  of  the  fertilized  egg.  His  results 
are  for  the  most  part  confirmatory  of  his  former  observations,  J  and  are 
briefly  as  follows  : — 

Before  impregnation,  the  germinal  vesicle  becomes  profoundly 
altered ;  its  membrane  disappears,  and  itself  assumes  a  spindle  form, 
with  the  usual  radiation  of  granules  from  its  poles.  It  then  approaches 
the  periphery  of  the  egg,  and  one  end  of  it  passes  into  a  small  pro- 
minence on  the  surface  of  the  latter.  The  spindle  then  divides  in  the 
usual  way,  one  part  remaining  in  the  egg  proper,  the  other  in  the 
prominence,  which  now  becomes  separated  off  as  the  first  polar  cell. 
The  same  process  is  gone  through  once  more,  and  another  polar  cell 
formed.  The  portion  of  the  nucleus  still  left  in  the  egg  now  undergoes 
a  change,  becoming  converted  into  a  rounded  body — the  female  pro- 
nucleus— surrounded  by  radiating  granules.  At  about  this  time,  or 
somewhat  before,  fertilization  takes  place,  usually  a  single  sperma- 
tozoon making  its  way  into  the  vitellus,  whereupon  its  tail  undergoes 
absorption  and  its  head  is  converted  into  a  body — the  male  pronucleus 
— closely  resembling  the  female  pronucleus.  The  two  pronuclei  travel 
towards  one  another,  coalesce,  and  produce  by  this  process  of  conjuga- 
tion, the  first  cleavage-nucleus  of  the  impregnated  egg. 

Digestion  of  Albuminoids  by  Invertebrata.  —  The  researches 
of  Dr.  Fredericq  have  been  directed  to  Annelids,  a  cestoid  Worm, 
Molluscs,  Ascidians,  a  Bryozoon,  an  Echinoderm,  a  Ccelenterate  and 
some  Sponges.  He  treats  the  digestive  organs  of  the  animal,  if  they 
are  large  enough  to  be  isolated,  with  alcohol.  If  the  animals  are  too 
small  he  places  a  considerable  number  of  them  entire  in  the  alcohol, 
which  coagulates  the  albuminoid  bodies,  sparing  the  ferments.  The 
objects  thus  treated  are  dried  and  pulverized,  and  the  powder  should 
contain  the  ferments.  To  distinguish  them,  one  part  of  the  powder  is 
infused  in  distilled  water,  another  part  in  water  acidulated  with 
muriatic  acid,  and  a  third  with  water  alkalized  by  carbonate  of  soda. 
A  piece  of  fibrin  placed  in  the  different  liquids,  heated  to  40°,  indi- 
cates by  its  solution  or  resistance  the  presence  or  absence  of  ferments 
analogous  to  pepsine  or  thrypsine. 

The  general  result  was  found  to  be  that  the  transformation  of 
aliments  is  effected  in  the  Invertebrata  by  digestive  ferments  analogous 
to  those  of  the  Vertebrata.§ 

*  Vol.  vii.  (1878)  251. 

t  'Morphol.  Jahrb.,'  iv.  (1878)  156  and  177. 
X  See  Balfour,  in  'Quart.  Journ.  Mikr.  Sci.,'  xviii.  (1878). 
§  'Bull.  Acad.  Roy.  Sci.  Belg.,'  xlvi.  (1878);  'Rev.  Internat.  des  Sci.,'  iii. 
(1879)  80. 


NOTES    AND    MEMORANDA.  275 

Eozoon  Canadense. —  Dr.  Dawson,  F.R.S.,  writing  on  Professor 
Mobius'  recent  treatise,  says  *  that  Eozoon  Canadense  has  since  the 
first  announcement  of  its  discovery  by  Logan  in  1859,  attracted  mnch 
attention,  and  has  been  very  thoroughly  investigated  and  discussed, 
and  at  j^resent  its  organic  character  is  generally  admitted.  Still  its 
claims  are  ever  and  anon  disputed,  and  as  fast  as  one  opponent  is  dis- 
posed of,  another  appears.  This  is  in  great  part  due  to  the  fact  that 
so  few  scientific  men  are  in  a  position  fully  to  appreciate  the  evidence 
respecting  it.  Geologists  and  mineralogists  look  upon  it  with  sus- 
picion, partly  on  account  of  the  great  age  and  crystalline  structure  of 
the  rocks  in  which  it  occurs,  partly  because  it  is  associated  with  the 
protean  and  disputed  mineral  serjientiue,  which  some  regard  as  erup- 
tive, some  as  metamorphic,  some  as  psoudomorphic.  The  biologists 
on  the  other  hand,  even  those  who  are  somewhat  familiar  with  fora- 
miniferal  organisms,  are  little  acquainted  with  the  appearance  of  these 
when  mineralized  with  silicates,  traversed  with  minute  mineral  veins, 
faulted,  crushed  and  partly  defaced,  as  is  the  case  with  most  specimens 
of  Eozoon.  Nor  are  they  willing  to  admit  the  possibility  that  these 
ancient  organisms  may  have  presented  a  much  more  generalized  and 
less  definite  structure  than  their  modern  successors.  Worse,  perhaps, 
than  all  these,  is  the  circumstance  that  dealers  and  injudicious  amateurs 
have  intervened,  and  have  circulated  specimens  of  Eozoon  in  which 
the  structure  is  too  imperfectly  preserved  to  admit  of  its  recognition, 
or  even  mere  fragments  of  serpentinous  limestone,  without  any  struc- 
ture whatever.  He  has  seen  in  the  collections  of  dealers  and  even  in 
public  museums,  specimens  labelled  "  Eozoon  Canadense  "  which  have 
as  little  claim  to  that  designation  as  a  chip  of  limestone  has  to  be 
called  a  coral  or  a  crinoid. 

The  memoir  of  Professor  Mobius  affords  illustrations  of  some  of 
thtse  difficulties  in  the  study  of  Eozoon.  Professor  Mobius  is  a 
zoologist,  a  good  microscopist,  fairly  acquainted  with  modern  fora- 
minifera,  and  a  conscientious  observer  :  but  he  has  had  no  means  of 
knowing  the  geological  relations  and  mode  of  occurrence  of  Eozoon, 
and  he  has  had  access  merely  to  a  limited  nmuber  of  specimens 
mineralized  with  serpentine.  These  he  has  elaborately  studied,  has 
made  careful  drawings  of  portions  of  their  structures,  and  has 
described  these  with  some  degree  of  accuracy  ;  and  his  memoir  has 
been  profusely  illustrated  with  figures  on  a  large  scale.  This,  and 
the  fact  of  the  memoir  appearing  where  it  does  (Palseontographica), 
convey  the  impression  of  an  exhaustive  study  of  the  subject ;  and 
since  the  conclusion  is  adverse  to  the  organic  character  of  Eozoon, 
this  paper  may  be  expected,  in  the  opinion  of  many  not  fully  acquainted 
with  the  evidence,  to  be  regarded  as  a  final  decision  against  its  animal 
nature.  Yet,  however  commendable  the  researches  of  Mobius  may 
be,  when  viewed  as  the  studies  of  a  naturalist  desirous  of  satisfying 
himself  on  the  evidence  of  the  material  he  may  have  at  command,  they 
furnish  only  another  illustration  of  partial  and  imperfect  investiga- 
tion, quite  unreliable  as  a  verdict  on  the  questions  in  hand. 

Dr.  Dawson  then  "  indicates  the  weak  points  of  the  memoir,"  of 
which  the  following  is  a  summary. 

*  'Am.  Jour.  Sci.  and  Arts,'  xvii.  (1879)  196. 

T    2 


276  NOTES   AND    MEMORANDA. 

1.  There  are  errors  and  omissions  from  want  of  study  of  tlie  fossil 
in  situ,  and  from  want  of  acc[uaintance  with  its  various  states  of 
preservation. 

2.  He  confounds  the  finely  tubulated  proper  wall  of  Eozoon  with 
the  chrysotile  veins  traversing  many  of  the  specimens  and  obviously 
more  recent  than  the  bodies  whose  fissures  they  fill. 

3.  In  regard  to  the  canal  system,  he  thinks  that  the  round  and 
regularly  branching  forms  which  he  figures,  and  which  nearly  resemble 
the  similar  parts  of  modern  Foraminifera,  are  rather  exceptional,  which 
is  a  mistake. 

4.  A  fatal  defect  in  his  mode  of  treatment  is  that  he  regards  each 
of  the  structures  separately,  and  does  not  sufficiently  consider  their 
cumulative  force  when  taken  together. 

Reticularian  Rhizopoda. — Mr.  H.  B.  Brady,  F.R.S.,  in  notes  on 
some  of  the  Reticularian  Rhizopoda  of  the  '  Challenger'  Expedition,*  re- 
ferring to  Carpenter,  Parker,  and  Jones's  '  Introduction  to  the  Study 
of  the  Foraminifera,'  the  work  of  Professor  Reuss,  and  the  more  recent 
suggestions  of  Professor  Zittel  and  Professor  T.  Rupert  Jones,  as  to 
classification,  says  that  it  is  not  altogether  satisfactory  to  have  to 
depend  solely  upon  the  structure  and  conformation  of  the  external 
skeleton  or  test  for  distinctive  characters.  There  can  scarcely  be  a 
doubt  that  the  sarcode  bodies  of  animals  varying  so  much  in  their 
features  must  have  important  differences.  The  researches  of  R.  Hert- 
wig  on  the  animal  of  Miliola  and  Iiotalia,'\  and  those  of  F.  E.  Schulze ;}: 
on  Polystomella  and  Lagena,  permit  no  longer  the  belief  that  the 
Reticularian  Rhizopoda  consist  of  mere  masses  of  undifferentiated 
protoplasm,  and  a  wide  field  of  investigation  is  thereby  opened,  in 
which  the  employment  of  chemical  reagents,  in  conjunction  with  the 
higher  powers  of  the  Microscope,  may  be  expected  to  yield  a  harvest 
of  hitherto  unnoted  facts.  But  for  these  methods  of  research  the 
fresh,  if  not  the  living  animal  must  be  used  ;  material  long  preserved 
in  alcohol,  as  the  '  Challenger  '  dredgings  have  necessarily  been,  fur- 
nishes only  the  knowledge  derivable  from  the  harder  tissues,  and  the 
portions  rendered  permanent  by  inorganic  constituents. 

Protozoa  of  Northern  Russia.  —  An  elaborate  paper  on  this 
subject,  illustrated  by  two  plates,  by  C.  von  Mereschkowsky,  §  gives 
the  results,  as  far  as  Protozoa  are  concerned,  of  his  two  journeys  to 
the  White  Sea,  made  in  the  summers  of  1876  and  1877. 

1.  Proposed  new  Family. — Mereschkowsky  proposes  to  form  into 
the  new  family  JJvellina  those  colonial  monads  the  individuals  of 
which  are  provided  with  one  or  more  cilia,  are  devoid  of  a  lorica,  but 
sometimes  enclosed  in  a  common  gelatinous  investment,  are  not 
united  into  a  branched  colony,  but  form  more  or  less  spherical  masses, 
and  for  the  most  part  [Anthophjsa  is  an  exception)  are  free-swimming. 
They   may,   in  the  author's  opinion,    be  taken  as  transition  forms 

*  'Quart.  Journ.  Micr.  Sci.,'  xix.  (1879)  24. 
t  '  Jenaisclie  Zeitscbrift  fiir  Natunviss.,'  x.  42. 
X  '  Archiv  fiir  Mikr.  Anat.,'  xiii. 
§  Ibid.,  xvi.  (1879)  153. 


NOTES   AND    MEMORANDA.  277 

between  unicellular  and  multicellular  animals,  and  indeed  as 
representing  permanent  Moridce.  Multiplication  takes  place,  in  fact, 
by  the  separation  of  a  monadiform  cell  and  its  division  into  2,  4, 
8,  &c.,  masses,  by  a  process  exactly  resembling  the  segmentation  of  the 
egg-cell  in  a  Metazoon.  Polytoma  uvella  is  not  included  in  this 
family,  since  the  morula  form  is  not  permanent,  but  breaks  up  into 
separate  individuals. 

2.  Neiv  Genera. — The  following  three  genera  are  described  as 
being  new  to  science.  MerofricJia  (^M.bacillata),  a  regularly  oval  uni- 
flagellate monad  ;  JJrceolus  (  U.  Alenizini),  another  uniflagellate  monad, 
with  transparent  collar-like  oesophagus  ;  and  Kaeckelina^  (H.  horealis), 
a  beautiful  and  highly  interesting  marine  Moneron,  which  seems  to 
bear  much  the  same  sort  of  relation  to  the  Tentaculifera  (Acineta, 
Podopliyra,  &c.),  as  Protamoeba  bears  to  Amoeba,  Myxastrum  to  the 
Gregarinidce  and  Protomonas  to  the  monads.f  It  consists  of  a  globular 
colourless  body,  capable  of  very  slight  changes  of  form,  devoid  of 
vacuole  or  nucleus  but  containing  various  granules.  Its  surface  is 
closely  beset  with  a  great  number  of  very  delicate  stiff  pseudopodia, 
standing  out  at  right  angles  to  its  surface,  and  about  equal  in  length 
to  the  diameter  of  the  bcdy.  The  body  is  seated  on  one  end  of  a 
stem,  the  other  extremity  of  w^hich  is  attached  to  foreign  bodies  (algfe). 
The  stem  is  long,  slender,  transparent,  and  solid,  being  quite  devoid 
of  an  axial  "  muscle."  Nothing  is  known  of  the  reproduction  of  this 
interesting  species. 

3.  New  Species. — The  author  describes  a  large  number  of  new 
species,  which  our  space  merely  allows  us  to  enumerate.  They  are 
Cothurnia  arcuata  (marine),  Vorticella  pyrum  (do.),  Zoothamnium  ma- 
rinum  (do.),  Ejjisfylis  balanorum  (do.),  Tintinnus  Ussowi  (do.),  Oxytricha 
Wrzesnioicskii  (do.),  0.  oculata  (do.),  Aspidisca  Andreeivi  (do.),  Balan- 
iidlum  (?)  medusarum  (do.).  Glaucoma  Wrzesnioicskii  (fresh-water), 
Holophrya  Kessleri  (do.),  Podophyra  (Acinefa)  conipes  (marine),  Dino- 
physis  arctica  (do.),  Htteromita  sulcata  (fresh-water),  H.  cylindrica 
(marine),  H.  adunca  (do.),  Clathrulina  CienJcowskii  (fresh-water),  Pleuro- 
phrys  angulafa  (do.),  Difflugia  Solowetskii,  Hyalodiscus  Korotnewi 
(marine).  Amoeba  minuta  (do.),  A.  papillata  (fresh-water),  A.  angulata 
(do.),  A.  Jelaginia  (do.),  A.  emittens  (do.),  A.  alveolata  (marine),  A. 
filifera  (do.),  and  Protamoeba  Grimmi  (do.). 

4.  Geograjjliical  Distribution  of  Infusoria.  —  The  author  sums 
up  his  remarks  on  this  question  in  the  form  of  three  proposi- 
tions. He  considers  it  well  established,  firstly,  that  the  marine 
Infusorial  fauna,  being  ex;  osed,  like  any  other  animal  fauna,  to  the 
influence  of  external  conditions,  is  wholly  different  to  that  of  fresh 
water.  Secondly,  that  the  infusorial  (protozoicj  faunas  of  different 
seas,  distinguished  from  one  another  by  unlike  conditions,  are  them- 
selves different,  and  this  difference  is  of  the  same  character  as  that 
existing  in  any  group   of  the  higher   animals.      Thirdly,  that  the 

*  This  name  has  beeu  api)lied  by  Bessels  to  SaiidaM's  Astrorhiza.  See 
'Quart.  Journ.  Micr.  Sci.,'  xvi.  221. 

t  See  the  table  on  p.  677  of  Huxley's  '  Invertebrata,'  giving  the  relations  of 
the  various  geueia  of  Monera  to  the  groups  of  Endoplastica.  The  discovery  of 
Haeckelina  fills  up  an  important  gap  in  this  scheme. 


278  NOTES    AND    MEMORANDA. 

marine  protozoic  fauna  differs  far  more  in  different  seas  than  does 
the  fresh- water  protozoic  fauna  in  different  terrestrial  regions. 

Deep-sea  Siphonophora. — The  Siphonophora  have  always  been 
held  to  be  an  exclusively  surface  group ;  it  is  therefore  of  great 
interest  to  find  species  of  the  sub-order  occurring  at  great  depths. 
Professor  Studer  of  Bern  gives  an  account  *  of  two  well-marked  species 
brought  up  di;ring  the  voyage  of  the  corvette  '  Gazelle,'  from  depths  of 
1500-2000  fathoms  in  the  Atlantic  Ocean.  Both  species  belong  to 
the  genus  Bhizophysa,  and  are  named  by  Studer  B.  conifera  and  B. 
inermis.  Full  descriptions,  illustrated  by  three  plates,  are  given  of 
both  forms,  as  well  as  of  some  fragmentary  sj)ecimens  of  other 
Siphonophora  found  at  the  same  time. 

Strange  Anomaly  among  the  Hydromednsae.— In  the  '  Transac- 
tions of  the  Society  of  Naturalists  of  St.  Petersburg,'!  a  new  species  of 
small  naked-eyed  Medusa,  from  the  White  Sea,  is  described,  which 
Mereschkowsky  has  named  Bougaiuvillea  paradoxa,  and  which  (with 
another  species  of  the  same  genus)  presents  a  strange  anomaly  pretty 
frequently  observed  amongst  the  normal  individuals. 

The  adult  animal  does  not  much  exceed  1  cm.  in  length,  and 
its  form  is  that  of  a  bell  slightly  contracted  at  its  aperture,  with  four 
radiating  canals,  each  furnished  at  its  extremity  with  a  tuft  of  from 
three  to  seven  tentacles  and  with  a  red  ocellus.  The  deep  red  manu- 
brium has  from  above  the  form  of  a  cross,  from  each  of  the  four  ends 
of  which  starts  a  radiating  canal.  Round  the  mouth  there  is  a  circle 
of  four  tentacles  dividing  dichotomously  into  a  great  number  of 
branches.  It  is  remarkable  that  the  ova  are  developed  immediately 
on  the  surface  of  the  manubrium,  so  that  the  latter  when  the  ova  have 
become  converted  into  planulie  acquires  a  tuberculate  aspect,  caused  by 
a  great  quantity  of  planulee  forming  a  layer  covering  its  surface,  with 
one  of  their  ends  projecting  freely,  and  the  other  attached  to  the  wall 
of  the  manubrium. 

Some  forms  (undoubtedly  of  this  same  animal)  are  distinguished  by 
the  total  absence  of  the  coloured  manubrium.  It  was  thought  that 
there  might  be  some  atrophy  of  the  organ,  but  remains  of  it  were 
sought  for  in  vain.  The  whole  gastro-vascular  system  consisted  only 
of  a  circular  canal  and  of  the  four  radial  canals,  which  were  united  at 
the  summit  without  forming  anything  resembling  a  stomach.  More- 
over, although  in  other  respects  of  normal  conformation,  it  had  abso- 
lutely no  opening  to  the  exterior,  no  buccal  or  other  aperture  which 
might  establish  a  communication  with  the  circumambient  water. 

This  fact  is  the  stranger  because  these  anomalies  are  observed  in 
MedusiB  which  are  but  very  little  exceeded  in  size  by  the  normal 
adult  individuals.  They  consequently  liave  been  able  to  nourish 
themselves,  since  from  microscnpic  embryos  they  have  attained  a  size 
of  more  than  half  a  centimetre. 

M.  Mereschkowsky  considers  that  the  only  probable  hypothesis 
to  account  for  the  development  of  a  complete  Medusa,  without  the  aid 

*  '  Zeitschrift  f.  wiss.  Zool.,'  xxxi.  (1878)  1. 

t  '  Protocolles  de  la  Reunion  du  14  Jau.  1878,'  ix.  33. 


NOTES   AND    MEMORANDA.  279 

of  organs  of  nutrition,  is  that  the  ectoderm  fulfils  the  function  of  the 
entoderm,  and  the  animal  nourishes  itself  by  its  ectoderm  absorbing  the 
organic  material  dissolved  in  sea  water,  a  supposition  the  more  pro- 
bable as  he  has  already  demonstrated  the  same  fact  in  sponges.* 

Muscle-epithelium  in  Anthozoa — Dr.  0.  Kling  publishes  a  pre- 
liminary communication  on  this  subject,  f  in  which  he  studies  the 
exact  relation  of  the  so-called  neuro-muscle  cells  in  the  genera  Adi- 
nozoa,  namely  Actinia  (^equina')  and  Muricia.  In  both  these  genera  he 
finds  that  the  muscular  layer  occurs  on  the  inner  (endodermal)  side 
of  the  supporting  lamella,  and  that  the  cells  of  which  it  is  composed 
are  in  evident  connection  with  the  endodermal  cells. 

The  arrangement  in  these  forms  is  therefore  the  exact  opposite  to 
those  which  obtain  in  Hydra,  in  which,  as  Kleinenberg  showed,  the 
neuro-muscular  cells  are  undoubtedly  ectodermal.  This  seems  to 
show  that  the  mesoderm,  like  the  generative  products,  may  have 
originally  sprung  indilferently  from  either  layer. 

Phylogeny  of  the  Antipatharia. — This  subject  is  discussed  in  a 
paper  |  by  G.  v.  Koch,  who  begins  with  a  description  oi  Antipathes  larix 
and  Gephyra  Dohrnii,  and  afterwards  discusses  the  probable  steps  in 
the  evolution  of  the  Antipatharia,  which  he  considers  to  have  been 
as  follows : — 

1.  Soft-bodied  Actinice  secreted  a  horny  substance  from  the  ecto- 
derm of  the  disk  of  attachment. 

2.  Those  of  the  foregoing  forms,  which  were  attached  to  thin 
cylindrical  supports,  surrounded  the  latter  and  covered  them  with  a 
horny  substance,  which,  in  the  case  of  polypes  occurring  in  large 
groups,  served  to  unite  them  by  their  bases. 

3.  These  polypes,  living  singly  or  in  groups,  became  united,  by 
means  of  stolons,  into  a  colony.  The  axial  skeleton  no  longer  existed 
exclusively  as  an  investment  to  some  support,  but  gave  off  independent 
branches. 

4.  The  separate  parts  of  the  polypes  underwent  retrogression. 

5.  The  colonies  (zoanthodemes)  assumed  a  greater  independence 
of  form,  while  the  axial  skeleton  no  longer  retained  the  form  of  an 
investment  of  a  foreign  support.  The  polypes  decreased  in  size 
concomitantly  with  the  increase  of  their  numbers  on  one  colony  ; 
with  this  diminution  in  size  was  connected  arrest  of  the  mesenteries 
and  tentacles. 

Skeleton  of  the  Alcyonaria. — A  study  of  this  interesting  group 
of  Actinozoa  has  been  made  by  v.  Koch.§  In  the  first  part  of  the  paper 
the  author  gives  a  description  of  the  anatomical  character  of  the 
following  genera  and  species  : — Sderogonia  Mexicana,Mopsea  erythrcea, 
Melithcea,  Muricea  placomus,  Isis  elongata,  Primnoa  verticillans,  Penna- 
tula  rubra,  Haliscepfrum  Gustavianum,  and  Kophobelemnon  Leuckartii. 

The  second  part  is  occupied  with  a  description  of  the  skeleton  of 

♦  'Ann.  and  Mag.  of  Nat.  Hist.,'  iii.  (1879)  177. 

t  '  Morphol.  Jahrb.,'  iv.  (1878)  327. 

X  Ibid.,  iv.  (1878)  74.  §  Ibid.,  iv.  (1878)  447. 


280  NOTES    AND    MEMORANDA. 

Alcyonaria,  and  begins  with  a  brief  general  description  of  the  skeleton 
of  Actinozoa.     This  may  occur  in  either  of  the  following  positions  : — 

o    w-.,^-*"  ^!.^^  ^'1"f  ^  '"'^''''^  ''^  ''^^  entoderm!  Entoskeleton. 

2.  Within  the  entoderm j 

3.  Between  the  entoderm  and  ectoderm —         1 

a    Secreted  from  entoderm  cells  only     . .     Mesoskeleton. 

0.  From  both  layers j 

c.  From  ectoderm  cells  only J 

4.  Within  the  ectoderm "I   jrcfoajjeieton 

5.  On  the  free  (outer)  surface  of  the  ectoderm  / 

Of  these  only  the  third  and  fifth  kinds  occur  in  Alcyonaria. 

The  mesoskeleton  in  the  simple  forms  consists  of  "  a  thinner  or 
thicker  layer  between  the  ectoderm  and  entoderm,  which,  after  removal 
of  all  the  cellular  elements  of  the  body,  retains  the  form  of  the  polype, 
since  it  extends  between  all  the  folds  of  the  two  primary  cell-layers." 

In  those  compound  forms  which  have  the  polypes  connected  by 
stolons,  the  mesoskeleton  exists  in  tbe  form  of  a  thin  lamella  between 
the  two  layers  of  the  stolons.  In  the  species  in  which  the  polj'^pes  are 
united  into  a  broad  plate-like  colony  by  means  of  a  solid  mass  or 
coenenchyma,  the  greater  part  of  the  latter  is  formed  by  the  meso- 
skeleton, which  is  covered  externally  by  ectoderm,  while  within  are 
contained  the  nutritive  canals,  lined  with  entoderm,  by  means  of 
which  the  polypes  are  placed  in  communication  with  one  another. 

In  a  few  forms,  the  mesoskeleton  consists  merely  of  a  hyaline  or 
fibrillar  substance  [Monoxenia,  Cornularia).  In  other  cases  calcifications 
or  spicules  are  developed,  the  arrangement  of  which  differs  greatly, 
both  in  various  portions  of  the  same  polype  or  of  the  same  zoantho- 
deme,  and  in  the  various  genera  and  species.  The  spicules  are  often 
scattered  singly  in  the  hyaline  matrix,  but  often,  on  the  other  hand, 
exist  in  such  great  numbers  as  to  give  the  whole  skeleton  a  firm,  cork- 
like consistency,  its  form  being  then  but  slightly  altered  by  drying. 
In  many  cases  the  separate  spicules  undergo  fusion,  and  form  a  firm 
continuous  framework,  which  may  replace,  to  a  greater  or  less  extent, 
the  hyaline  matrix  (^Tuhijjora,  Pseudaxonia).  In  a  few  forms  there 
is  a  continuous  mesoskeleton,  not  due  to  the  fusion  of  originally 
distinct  calcifications.  The  free  part  of  the  polypes  and  tbe  pei'ij)heral 
portions  of  the  zoanthodeme  never  undergo  conversion  into  horn,  but 
only  the  so-called  axis  (pseudaxis,  Koch).  Calcification  of  the  horny 
interstitial  substance  has  not  been  made  out  in  Alcyonaria. 

An  ectoskeleton  occurs  only  in  the  tree-like  zoanthodeme,  and 
probably  also  in  Pennatulidce.  As  far  as  is  known,  it  consists  of  a 
secretion  of  the  ectoderm  cells  of  the  attached  surface ;  this  secretion 
increasing  with  the  growth  of  the  colony,  forms  a  horny  more  or  less 
calcified  axis  (the  sclerobase).  Frequently  cavities  occur  in  the 
horny  substance,  filled  either  with  a  spongy  material  {Gorgonia, 
Muricea),  or  by  a  crystalline  substance,  rich  in  calcific  matter  {Plexau- 
rella).  Often  there  is  an  alternation  of  horny  and  calcareous  lamellae, 
and  in  many  species  the  whole  axis  is  formed  of  alternate  horny  and 
calcareous  pieces.  On  the  other  hand,  the  horny  substance  may  be 
uniformly  impregnated  with  calcic  carbonate,  but  spicules  never  occur 
in  the  ectoskeleton.     The  central  part  of  the  axis  may  remain  empty 


NOTES    AND    MEMORANDA.  281 

or  be  filled  up  with  siDougy  tissue  traversed  by  cross-partitions ; 
secondary,  calcific  masses  may  also  be  found  in  the  cavities  of  the  axis. 
The  third  j^art  of  the  paper  is  classificatory :  the  author  divides 
the  various  families  of  the  Alcyonaria  into  three  chief  groups,  as 
follows : — 

I. — Polypes  never  united  into  a  colony. 

Fam.  1.  Haimeida. 
II. — Colonies  are  formed,  but  the  individual  polypes  remain  independent, 
and  are  only  united  by  stolons  or  by  plate-like  expansions. 
Fam.  2.  Cornularida. — Spicules  separate. 
„      3.  Tubiporida. — Spicules  united  into  a  continuous  ske- 
leton. 
III. — The  coenenchyma  is  well  developed,  and  the  polypes  appear  only  as 
organs  of  the  colony. 

a.  Mesoskeleton  only  developed. 

Fam.  4.  Alcyonida.  —  ^'kcleion  spicular. 
„      5.  Pscudaxonia. —  Skeleton  continuous. 
„      6.  Helisporida. — Main   part  of    skeleton  calcified ;    no 
sjiicules. 
6.  Both  meso-  and  ectoskeleton  developed. 

Fam.  7.  Pennatulida. — Free-swimming;      digestive     cavities 
long. 
„      8.  Axifera. — Fixed ;  digestive  cavities  short. 

New  Species  of  Isis. — A  new  species — Isis  Neapolitana — of  the 
interesting  Alcyonarian  order  Isidacece  has  been  recently  discovered  by 
V.  Koch,  who  gives  an  account  of  its  anatomy,*  together  with  the 
following  diagnosis :  — 

"  Polypary  about  1  metre  high,  ramified,  attached  to  rocks,  &c.  by 
means  of  an  irregularly  lobed  basal  plate,  branches  springing  from  the 
horny  internodes.  Calcareous  joints  of  the  axial  skeleton  white,  cylin- 
drical ;  on  the  thicker  stems  about  8  mm. ;  on  thinner  branches  about 
16  mm.  long,  strongly  ribbed.  Internodes  dark  brown,  becoming 
shortened  with  the  decrease  in  thickness  of  the  stem,  from  2  •  5  mm. 
to  0  •  3  mm.  in  length.  Coenenchyma  thin,  greyish-white,  containincf 
calcareous  spicules  only  in  the  bases  of  the  polypes.  Nutrient  canals 
twice  as  numerous  as  the  longitudinal  grooves  on  the  calcareous  joints. 
Polypes  scattered  over  the  branches,  about  3  mm.  long,  well  provided 
with  smaller  and  larger  spicules  ;  outer  wall  of  tentacles  also  containing 
spicules.     Polypes  very  slightly  contractile.    Habitat,  Gulf  of  Naples. 

The  paper  is  accompanied  by  a  plate,  illustrating  the  anatomy  of 
the  species. 

Gorg-onia  verrucosa — In  a  short  paper  on  the  anatomy  of  this 
species,t  v.  Koch  records  the  important  discovery  of  a  layer  of  eijithe- 
lial  cells  between  the  horny  axis  of  the  zoanthodeme  and  the  ccBnen- 
chyma.  He  has  found  the  same  thing  in  other  Gorgonice,  and  consi- 
ders it  certain  that,  in  some  at  least  of  the  horny  corals,  the  axial 
skeleton  is  a  secretion  of  an  epithelium  derived,  in  all  probability, 
from  the  ectoderm. 

This  discovery  is  of  great  interest,  as,  according  to  most  observers, 
the  axial  skeleton  of  Gorgonidce  is  formed  from  the  connective  tissue  of 
the  coenenchyma ;  Koch  himself,  indeed,  assigns  this  origin  to  it  in  Isis. 
*  'Morphol.  Jahrb.,'  iv.  (1878)  112.  f  Ibid.,  269. 


282  NOTES    AND    MEMORANDA. 

Prehensive  Cells  in  the  Ctenophora. — Dr.  Carl  Chun  gives  *  an 
account  of  his  observations  on  certain  prehensive  cells  which  have 
been  observed  in  the  Ctenophora ;  those  which  are  found  on  the 
"  grappling  lines  "  of  these  forms  were  principally  studied  in  Cydippe 
hormiphora,  Gegbr.  The  bodies  in  question  were  but  -j-^^  of  a  milli- 
metre in  breadth,  and  were  chiefly  made  up  of  gelatinous  tissue,  just 
as  is  the  greater  part  of  the  body  of  these  Coelentera ;  they  contain  a 
filament,  coiled  into  five  or  seven  spires,  which,  when  fully  extended, 
has  much  the  form  of  Vorticella  ;  nor  does  the  resemblance  end  here, 
for  the  thread  may  be  seen  to  be  provided  with  a  muscular  band,  the 
functions  of  which  are  examined.  The  author  cori*ects  some  of 
Clark's  observations  on  these  so-called  "  Lasso-cells,"  and,  pointing 
out  that  they  are  not,  like  the  ordinary  thread-cells,  set  free  from  a 
containing  cell,  thanks  to  their  elasticity,  proposes  to  call  them 
"  Greif-zellen."  He  adds  that  he  has  failed  to  find  true  stinging-cells 
(nematocysts)  in  the  Ctenophora,  and  urges  that  they  cannot  be 
regarded  as  belonging  to  the  Nematophorous  group. 

Australian  Corals — The  Eev.  J.  E.  Tenison-Woods,  in  the  '  Pro- 
ceedings of  the  Linnean  Society  of  New  South  Wales,'  f  says  that  a 
study  of  the  Australian  living  forms  has  shown  that  some  of  the  fossil 
species  thought  to  be  extinct  are  still  existing.  They  are  Trocho- 
cyatlms  Victorice  and  Sphenotrochus  variolaris.  There  are  also  forms 
which  have  a  remarkable  relation  with  extinct  species,  viz.  Conocyathus 
Zelandice,  which  was  not  known  as  Australian,  and  which  bears  a 
strong  resemblance  to  the  extinct  European  Miocene  form  C.  sulcatus. 
It  would  be  almost  useless  to  form  any  conclusions  from  the  very  few 
observations  which  have  resulted  in  the  discovery  of  a  few  new 
species,  yet  what  has  been  discovered  shows  plainly  what  might  be 
expected  from  an  extended  series  of  operations.  So  far  as  has  been 
learned,  the  coral  fauna  of  New  Zealand  is  very  distinct  from  the 
Australian.  If  the  observations  of  Quoy  and  Gaimard  are  to  be  relied 
upon,  the  northern  end  of  New  Zealand  possesses  forms  which  are 
never  found  out  of  the  tropics  in  Australia,  and  very  far  within  the 
tropics  as  well — Poriles  Gaimardii  and  Polyphyllia  pelvis.  Among 
the  simple  corals  C.  Zelandice  is  the  only  form  known  as  common  to 
both  Australia  and  New  Zealand. 

The  only  corals  on  the  S.  and  S.E.  coast  of  Australia  which  could 
in  any  sense  be  called  reef-building  forms  are  one  or  two  species  of 
Stylaster  and  one  or  two  of  Plesiastrcea.  Both  of  these  are  littoral 
and  grow  in  tufts  or  small  masses,  but  never  in  anything  more  than 
the  merest  patches. 

Eleven  new  species  are  described  and  figured,  for  two  of  which  the 
author  has  erected  two  new  genera.  One,  DunocyatJius  (parasiticus),  is 
a  parasitic  coral  of  minute  size,  growing  on  the  base  of  the  singular 
Polyzoary  named  by  Professor  Busk  Lunulitcs  cancellata ;  the  other, 
Crispatotrochus  (inornatus),  a  form  which  approximates  to  Cerato- 
trochus,  but  differs  in  the  absence  of  any  special  ornamentation  on  the 

*  'Zool.  Anzeiger,'  i.  (187S)  50. 

t  Vol.  ii.  (1878)  292  :  "  Extratropical  Corals  of  Australia." 


NOTES    AND    MEMORANDA.  288 

ribs   and   tlie   wide,  deep  calice,  with   a   large  hispid   and   spongy 
columella  and  a  broad  attachment. 

Amongst  the  new  species  the  author  has  been  able  to  add  one  to 
each  of  the  remarkable  and  rare  genera  Endopachys  [Australic^),  and 
Heteropsammia  {^ellipticd).  The  author  also  in  other  papers  describes 
a  new  species  oi  Psammoseris — P.  cylicioides* — and  of  Desmophyllum — 
D.  quinarium,  f  — the  former  with  a  plate  of  eight  figures. 

New  Genus  of  Milleporidse. — In  the  same  publication  theEev.  J.  E. 
Tenison- Woods  describes  |  a  new  genus  of  Milleporid^,  Arachnopora, 
the  generic  character  being  "  zoothome  parasitic  spreading  like  a  small 
thin  web  over  other  corals."  In  the  only  species  found  {A.  argentea) 
the  substance  of  the  zoothome  (7  by  3  mm.)  seems  a  quite  transparent 
membrane,  on  which  there  is  generally  a  very  close  arrangement  of 
small  silvery  granules.  It  occurs  parasitic  on  corals,  filling  up  half  of 
the  calice  and  spreading  from  opposite  septa  like  a  spider's  web. 
It  also  spreads  over  tlie  sides  of  the  costse,  where  it  appears  just  like 
a  snail's  track,  on  which  some  very  fine  white  dust  had  been  sparsely 
scattered.     There  are  no  calices  on  the  outside. 

New  Genus  of  Starfishes.  —  Dr.  J.  Jullieu  describes  §  a  new 
genus  Marthasterias  allied  to  Asterias,  and  characterized  by  its  four 
rows  of  ambulacral  tubes,  the  reticulated  character  of  the  dorsal 
skeleton,  five  arms,  the  presence  of  spines  in  the  membrane  edging  the 
marginal  plates,  and  its  pedunculated  pedicellariae :  to  the  new  species 
the  name  foliacea  is  given. 

Some  idea  of  its  characters  will  be  gathered  from  the  fact  that 
"  an  eminent  zoologist  "  regarded  it  as  an  Asterias  glacialis  which 
had  undergone  violent  compression  ;  this  theory  is,  however,  nega- 
tived by  the  presence  on  the  dorsal  surface  of  fragments  of  Betepora 
cellulosa,  which  would  not  have  been  preserved  had  the  animal 
undergone  the  accident  suggested.  The  rows  of  ambulacral  spines 
are  moreover  single,  and  not  double  as  in  AMerias ;  while  the  spines 
themselves  are  simply  conical,  and  are  without  the  median  constric- 
tion observed  in  that  common  form.  The  habitat  of  the  single  specimen 
described  is  not  quite  certainly  known,  but  it  is  stated  to  be  the 
Adriatic  ;  the  presence  of  a  young  Nassa  reticulata  in  its  intestines, 
together  with  that  of  the  above-mentioned  bryozoan  on  its  surface, 
seems  to  indicate  sufficiently  clearly  that  it  is  an  inhabitant  of  some 
European  sea. 

Helminthology. — Linstow  continues,  in  the  'Archiv  fiir  Natur- 
geschichte,'  ||  his  observations  on  Helminthology  ;  the  paper  is  purely 
technical,  but  it  may  be  of  interest  to  observe  that  this  indefatigable 
observer  here  describes  forty-two  forms,  of  which  twenty-four  are 
new  species.  The  last  described  is  the  curious  Sphcerularia  bombi, 
Dufour,  and  the  author  states  that  he  has  found  in  the  roots  of  moss  a 
Nematode  form,  which  is  very  like  it,  though  somewhat  larger,  and 

♦  '  Proc.  Linnean  Soc.  N.  S.  Wales,'  iii.  (1878)  8. 
t  Ibid.,  17.  X  Ibid.,  6. 

§  '  Bull.  Soc.  Zool.  de  France,'  iii.  (1878)  HI. 
II  xliv.  (1878)  218. 


284  NOTES    AND    MEMORANDA. 

witli  a  thicker  caudal  region.  lu  the  genus  Ascai-is  there  are  two 
series  of  hirval  forms,  one  with  and  one  without  a  boring  denticle  ;  of 
the  former  series  the  larvte  of  A.  capsularia,  A.  eperlani,  and  A.  com- 
munis are  of  a  relatively  enormous  size.  The  paper  is  illustrated  by 
three  plates. 

Excretory  Apparatus  of  Solenophorus  megalocephalus.  —  M. 
J.  Poirier  *  having  some  Solenophora,  which  had  only  remained  a 
short  time  in  alcohol,  injected  their  excretory  apparatus,  and  on 
examining  the  result  saw  that  it  did  not  agree  with  what  had  been 
hitherto  published. 

Instead  of  two  longitudinal  vessels  on  each  side  of  the  segments 
(the  mode  of  communication  between  them  not  having  been  hitherto 
noticed),  M.  Poirier  found,  as  in  Duthiersia,  six  such  vessels.  The 
two  internal  ones  alone  communicate  with  each  other  by  transverse 
canals,  situated,  as  in  all  the  Cestoids,  at  the  commencement  of 
each  segment.  These  vessels,  which  (with  the  exception  of  the  in- 
ternal ones)  have  in  the  segments  no  direct  communication  with 
each  other,  in  the  scolex  form  a  network  which  unites  them.  The 
external  vessel,  when  it  reaches  the  scolex,  buries  itself  more  deeply, 
passing  under  the  two  others  and  going  along  the  groove  which 
separates  the  two  bothridia,  towards  the  extremity  of  the  scolex ; 
there  it  divides  into  two  branches,  which  ramify  in  each  bothri- 
dium.  The  median  vessel,  of  a  smaller  calibre  than  that  of  the 
two  others,  passes  above  the  external  vessel,  and  about  the  middle  of 
the  length  of  the  scolex  bifurcates  into  two  branches  which  unite  to 
the  network  formed  by  the  divided  branches  of  the  external  vessel. 

The  internal  vessel  bifurcates  immediately  after  its  entrance  into 
the  head,  and  forms  a  network  of  very  large  meshes  which  is  joined 
to  the  network  of  smaller  meshes  arising  from  the  external  vessel. 
These  three  pairs  of  vessels  therefore  only  form  one  system. 

Besides  the  above  vessels,  which  are  of  a  considerable  size,  we 
find  on  the  surface  of  the  body,  a  second  system  of  fine  vessels,  which 
M.  Blanchard  j^ointed  out  some  time  ago  in  the  Tsenise  as  a  circulatory 
apparatus,  and  whose  existence  Gegenbauer  denies  altogether  in  his 
'  Comparative  Anatomy.'  These  vessels,  which  are  very  tine,  form  on 
the  surface  of  the  segments  and  of  the  scolex  a  network  of  rectangular 
meshes,  much  closer  in  the  Solenophora  than  in  the  Taeniae,  in  which 
the  longitudinal  vessels  of  this  network  are  few  in  number,  as 
M.  Blanchard  has  shown  in  Taenia  solium,  and  as  M.  Poirier  has 
proved  in  T,  crassicollis  of  the  cat.  This  network  is  only  inter- 
rupted ai'ound  the  genital  orifices :  according  to  M.  Blanchard  it  is 
completely  isolated,  but  in  reality  communicates  with  the  preceding 
system.  Indeed,  in  the  posterior  part  of  each  segment,  the  external 
vessel  of  the  first  system  sends  out  a  branch  as  far  as  the  edge  of  the 
segment,  and  there  produces  ramifications  which  go  into  the  external 
longitudinal  vessels  of  the  second  system.  The  other  vessels  of  the 
first  system  have  no  communication  with  these  fine  peripheral  vessels ; 
but,  as  they  reunite  in  the  scolex  with  the  external  vessel,  it  follows 

*  '  Comptes  Kendus,'  Ixxxvii.  (1878)1013. 


NOTES    AND    MEMORANDA.  285 

that  the  two  systems  communicate  and  only  form  one  single 
apparatus. 

The  fine  peripheral  vessels  communicate  by  very  fine  and  very 
short  vessels  with  the  calcareous  corpuscles  scattered  over  the  surface 
of  the  body. 

The  apparatus  must  therefore  be  an  excretory  apparatus.  It 
might  perhaps  also  serve  as  an  organ  of  absorption  and  nutrition,  the 
fine  peripheral  vessels  conducting  the  absorbed  products  into  the  large 
vessels,  which  would  distribute  them  into  the  deeper  parts  of  the 
organism. 

Anatomy  and  Embryogeny  of  the  Taeniadse. — A  preliminary 
communication  on  this  subject  by  M.  Monier  *  is  chiefly  a  revision  or 
criticism  of  the  results  of  Sommer  on  T.  mediocanellata  and  T.  solium  ; 
the  author  justly  observes  that  the  excellent  work  of  the  German 
helminthologist  seemed  to  be  one  which  would  be  for  a  long  time 
accepted  as  classical.  The  mother-cells  of  the  spermatozoids  are 
formed  in  the  midst  of  a  mass  of  central  tissue,  and  there  are  no 
proper  seminal  ducts  through  which  they  may  escape;  this  explains 
why  they  are  provided  with  that  long  and  aj^parently  useless  flagel- 
lum.  What  seminal  tubes  there  are,  are  formed  by  a  kind  of  excretion 
around  the  bundles  of  spermatozoids,  and  do  not  ordinarily  become 
easily  visible,  except  when,  as  in  T.  cerebralis,  they  are  pigmented. 
In  some  species  there  appear  to  be  two  sets  of  spermatozoids,  which 
become  mature  at  different  periods.  The  uterus  does  not  receive  the 
ova,  which  are  formed  in  just  the  same  place  and  in  just  the  same  way 
as  the  spermatozoids. 

The  Hauptdoiter  and  Nehendotter  of  Sommer  are  stated  to  be  merely 
extended  ectodermal  masses,  one  of  which — the  former — sometimes 
forms  a  kind  of  envelope  for  the  egg.  The  so-called  circular  muscular 
layer  is,  in  the  young,  found  to  give  off  fibres  to  the  interior  and  to 
the  exterior ;  these  fibres  are  separated  perij)herally  and  unite  at  their 
centre  to  form  the  "  parenchyma  "  ;  where  they  join  the  cuticle  they 
form  a  very  dense  layer.     Further  observations  are  promised. 

Parasites  of  the  LamellibrancMata. — TJlicnyf  gives  an  account 
of  some  observations  on  these  parasites. 

In  Cyclas  rivicola  he  finds  a  form  of  which  little  seems  to  be  known, 
although  it  appears  to  be  the  Cercaria  Cjjdadis  rivicolce  of  Diesing. 
These  forms,  which  were  found  in  sporocysts,  imbedded  in  the 
generative  organs  of  their  host,  were,  thanks  to  their  tail,  capable  of 
a  large  amount  of  movement ;  they  are  provided  with  a  terminal 
oval  sucker,  above  which  there  is  a  spine ;  in  the  anterior  part  of 
the  last  third  of  the  body  is  placed  the  ventral  sucker,  which  is  as 
broad  as  the  body.  The  most  interesting  region  is  the  terminal  or 
caudal  portion.  Connected  by  a  narrow  stalk  with  the  end  of  the 
body  there  is  a  pyriform  bulb,  the  surface  of  which  is  thrown  into 
a  number  of  folds  ;  the  interior  of  this  enlargement  is  filled  with  a 
thick  fluid,  in  which  small  vacuoles  may  be  frec[uently  observed,  and 

*  '  Rev.  Internat.  des  Sci.,'  ii.  (1878)  689. 

t  '  Arch,  fur  Naturgeschichte,'  xliv.  (1878)  211. 


286  NOTES   AND    MEMORANDA. 

it  is  also  enclosed  in  a  still  larger  bladder ;  the  walls  of  this  invest- 
ment are  invaginated  at  the  anterior  end,  so  as  to  form  an  aperture 
through  which  the  body  of  the  Cercaria  can  be  protruded ;  on  the 
other  hand,  the  whole  of  the  creature  may  be  at  times  observed  to  be 
retracted  within  this  envelope.  With  regard  to  this  last  no  explana- 
tion is  offered,  but  it  is  noted  as  non-existent  in  Cercaria  macrocerca, 
although  the  tail  of  this  form  has  a  proper  investment. 

Tlie  author  makes  some  observations  on  the  species  of  Buce- 
phalus which  infest  members  of  the  same  division  of  the  M(dlusca ; 
two  forms,  B.  polymorphus,  Baer,  which  lives  in  the  reproductive  organs 
of  Anodon,  and  B.  laimeanus,  Lacaze-Duthiers,  which  is  found  in 
marine  forms,  Cardimn  and  Ostrea,  are  already  known  ;  a  third,  which 
as  standing  between  the  other  two  is  very  appropriately  named  B. 
intermedins,  is  now  described ;  it  was  found  in  Anodonta  cellensis,  and 
the  peculiarities  of  its  structure  are  associated  with  its  caudal  region. 
In  B.  polymorphus  the  body  terminates  in  a  compressed  and  more  or 
less  biscuit-shaped  bulbous  enlargement,  the  broad  end  of  which  is 
attached  to  the  body  of  the  worm  ;  the  tail  connected  with  this  bulb, 
in  which,  it  should  be  said,  two  portions  can  be  made  out,  is  eminently 
variable  in  form  owing  to  its  great  power  of  contractility ;  in  the  new- 
species  the  two  parts  are  more  distinctly  differentiated  and  are  separated 
by  a  constriction,  but  the  caudal  portion  is  constantly  cylindrical  in 
shape,  and  its  only  power  of  change  is  limited  to  its  greater  or  less  ex- 
tension. When  several  forms  get  together  they  are  able  to  form,  with 
their  tails,  a  veritable  Gordian  knot,  which  no  instrument  can  unloose  ; 
in  this  point  it  differs  very  markedly  from  B.  polymorpTius,  the  tail  of 
which  can  by  very  slight  excitation  be  brought  to  change  its  form. 

New  Turbellarian. — The  sojourn  of  Mereschkowsky  on  the  White 
Sea  has  at  any  rate  produced  an  account  of  a  most  interesting 
Turbellarian,  to  which  he  has  given  the  name  of  Alauretta  viridiros- 
trum*  The  body  of  this  creature  was  elongated,  and  broadest  at  its 
anterior  end,  and  measured  -^^  of  a  millimetre ;  all  but  the  proboscis, 
which  was  green,  was  colourless,  and  fairly  transparent.  Seen  from 
without  there  appear  to  be  three  segments,  owing  to  the  presence  of 
two  circular  constrictions  towards  the  posterior  end.  By  the  aid  of 
fine  short  cilia  the  animal  moves  about  rapidly ;  these  cilia  are  found 
over  the  whole  body,  with  the  exception  of  the  very  anterior  region, 
where  a  single  seta  on  either  side  stands  directed  forwards  and  out- 
wards. The  integument  is  thick  and  is  succeeded  by  two  layers  of 
the  body  wall ;  of  these  the  inner  one  is  the  thicker,  and  is  distin- 
guished by  giving  off  five  projections  into  the  body  cavity,  which  give 
an  appearance  of  metamerism,  and  to  which  the  author  gives  at  least 
their  full  weight. 

The  mouth  is  placed  in  the  anterior  part  of  the  body,  where  it 
forms  an  ellipse-shaped  cleft ;  the  enteric  tube  is  straight,  and  does 
not  branch ;  the  position  of  the  anus  is  left  in  a  little  doubt.  The 
nervous  system  is  distinguished  from  that  of  all  other  Turbellaria, 
by  the  possession  of  a  large  number  of  bipolar  and  unipolar  nerve- 
cells  ;  the  eyes  are  on  either  side  of  the  nerve-centre. 
*  'Arch,  fiir  Naturgeschichte,'  xlv.  (1879)  35. 


NOTES   AND   MEMORANDA.  287 

The  apparent  segmentation  of  the  form  leads  the  author  to  inquire 
as  to  the  possibility  of  his  having  had  to  do  with  a  larval  Annelid  ;  all 
these  forms,  however,  seem  to  agree  in  that  they  do  not  exhibit  meta- 
meric  segmentation  till  a  late  period,  and  at  any  rate  not  until  they 
have  developed  setae  at  points  corresponding  to,  and  apparently  indi- 
cative of  such  segments ;  while  the  presence  of  sexual  products  in  the 
forms  observed  militates  against  their  being  immature.  Nor  again 
does  the  metamerism  seem  to  be  due  to  gemmation,  nor  is  it  the  first 
instance  of  such  an  arrangement;  Busch  recorded  a  case  in  1851,  the 
characters  of  which  w^ere  in  1865  put  by  Metschnikoff  in  their  true 
light,  while  the  Russian  naturalist  took  this  opportunity  of  recording 
another  example.     The  form  appears  to  belong  to  the  MicrostomecB. 

The  most  interesting  points  in  a  new  species  of  Prostomium  (P. 
horeale)  are  the  presence  of  a  chitinous  sabre-shaped  spine,  which  is 
placed  to  one  side  of  the  penis,  and  appears  to  be  an  organ  either  of 
defence  or  oifence,  and  of  a  collection  of  glandular  bodies  of  uncertain 
function,  set  on  either  side  of  the  base  of  the  proboscis.  In  another 
new  species  (P.  fapillatum)  Mereschkowsky  observed  the  presence  of 
six  papilliform  projections  at  the  anterior  end  of  the  body,  which 
serve  undoubtedly  as  tactile  organs. 

In  a  new  species  of  Mesostomium,  which  he  dedicates  to  L.  Graff, 
Mereschkowsky  describes  the  presence  of  enlargements  on  the  vessels, 
which  did  not  however  exhibit  either  contraction  or  pulsation,  and  the 
function  of  which  remains  obscure ;  they  do  not  seem  to  have  been 
hitherto  observed  in  these  forms. 

The  author  also  makes  some  remarks  on  Dinophilus  vorticoides, 
Oscar  Schmidt,  and  on  the  general  Turbellaria-Fauna  of  the  White 
Sea. 

Digestive  Organs  of  the  Fresh-water  Turbellarians.  —  Elias 
Metschnikoff,  who  in  1866  was  able  to  confirm  the  results  of  Claparede, 
made  three  years  earlier,  as  to  the  absence  of  an  alimentary  canal  in 
some  of  the  Rhabdoccelous  Planarians,  returns  to  the  subject,*  and 
points  out  that  the  results,  which  have  been  denied  by  Minot  on  a  priori 
grounds,  have  been  confirmed  by  Uljanin  (1870),  Salensky  (1872), 
and  much  more  lately  by  Graff.  He  further  proceeds  to  consider  how 
far  this  character  is  one  that  is  peculiar  to  these  forms,  and  which  so 
impressed  Uljanin  as  to  lead  him  to  give  to  them  the  name  of  Acoela, 
or  whether  it  is  not  rather  one  that  is  essentially  common  to  the 
whole  of  the  Tm'bellaria. 

His  account  of  the  modes  of  digestion  in  a  fresh-water  Turbel- 
larian  allied  to  Mesostomium  produdum,  and  in  M.  Ehrenbergii,  is  pecu- 
liarly interesting.  The  former  presented  a  fairly  irregularly  arranged 
mass  of  digestive  cells ;  in  these  cells  he  found  not  only  urinary  concre- 
tions, but  other  bodies  which  he  feels  compelled  to  regard  as  nutrient 
particles ;  in  M.  Ehrenbergii,  which  is  transparent,  he  was  able  to 
trace  the  history  of  these  particles  more  completely.  The  chief  food  of 
this  worm  is  Nais  prohoscidea,  and  an  hour  after  ingestion  he  was 
able  to  discover  all  the  soft  parts  of  the  Nais  in  its  enteric  cells ;  the 
cuticle  and  its  setae  alone  remained  in  the  lumen  of  the  tube.  To 
*  'Zool.  Anzeiger,'  i.  (1878)  387. 


288  NOTES    AND    MEMORANDA. 

test  the  matter  still  more  accurately  ho  attempted  to  feed  the  Meso- 
stomium  with  carmine,  but  iu  this  he  failed ;  the  Nais  was  however 
less  refractory,  and  he  thus  succeeded  in  getting  some  very  distinct 
points  of  observation  so  soon  as  the  jirey  had  been  devoured  by  the 
Turbellarian, 

Two  species  of  Planarians  were  fed  with  blood,  and  the  corpuscles 
were  soon  observed  in  the  cells  of  their  enteric  tube.  From  these 
observations  only  one  conclusion  is  possible :  there  are  Turbellaria 
which  ai'e  either  without  any  differentiated  digestive  system,  or  which 
have  retained  the  primitive  method  of  digestion,  that  namely  of  taking 
the  nutrient  particles  into  their  enteric  cells.  On  the  other  hand  it 
is  no  less  certain  that  there  are  forms  in  this  group  which  have  passed 
beyond  this  stage,  and  do  not  allow  the  nutriment  to  pass  into  the 
epithelial  cells  of  the  enteric  canal  until  they  have  been  subjected  to 
the  ordinary  digestive  process.  These  observations  are,  it  should  be 
observed,  of  great  importance  as  affording  au  examjile  of  the  like  of 
which  we  cannot,  in  the  present  state  of  the  evolution  question,  have 
too  many ;  for  it  bears  directly  on  that  variation  in  function  of  parts 
morphologically  the  same,  which  must  have  occurred  if  the  theory  of 
evolution  be  a  correct  explanation  of  morphological  facts. 

Land  Planarians.  —  Dr.  Kennel  states  in  the  '  Zoologischer 
Anzeiger,'  *  the  results  of  his  observations  on  Fasciola  terrestris, 
O.  F.  M.,  and  Geodesmus  bilineatus,  Metschnikoff,  the  two  forms  of  Land 
Planarians  found  in  Germany.  He  was  fortunate  enough  to  be  able 
to  get  a  specimen  of  the  former  which  produced  young  whilst  under 
observation,  and  he  notes  that  these  are  almost  completely  white.  His 
stiidy  of  the  generative  organs  leads  him  to  pretty  much  the  same  results 
as  did  those  of  Moseley  (on  Bhynchodemus).  The  two  ovaries  are  small 
rounded  capsules,  placed  very  near  the  anterior  end  of  the  body  ;  of 
the  testes  there  are  from  22  to  24  pairs,  set  close  together,  and  placed 
just  behind  the  ovaries.  The  common  efferent  duct  is  to  be  found  in 
the  last  third  of  the  body,  and  on  the  ventral  surface  it  leads  into 
the  narrow  canal  to  which  Minot  has  given  the  name  of  generative 
antrum ;  the  vagina  passes  back  from  it  and  ends  as  a  closed  sac, 
but  at  the  closed  end  there  open  into  it  on  either  side  the  oviducts ; 
the  uterus,  which  has  also  the  form  of  a  closed  sac,  opens  into  the 
vagina  ;  the  sheath  for  the  penis  is  pear-shaped,  and  the  well-developed 
penis  is  conical  in  shape. 

The  primitive  vascular  system  of  Moseley  is  regarded  as  forming 
the  longitudinal  nerves,  and  is  said  to  be  connected  with  a  well- 
developed  bilobed  cerebrum. 

Geodesmus  has  but  a  single  pair  of  testes,  and  there  is  no  csBcal 
sac  on  the  vagina ;  the  anterior  end  is  not  flat  (Metschnikoff),  but 
is  deeply  excavated  on  its  ventral  surface. 

Marine  Planarians. — Professor  Goette  gives  in  the  same  Journal  f 
a  short  account  of  his  observations  on  the  development  of  Marine 
Planarians.     He   finds   that  in    the   freshly   laid   eggs   of   Planaria 

*  '  Zool.  Anzeiger,'  i.  (1878)  26.  f  Ibid.,  75. 


NOTES   AND    MEMOBANDA.  289 

Neapolitana  the  extrusion  of  two  germinal  vesicles  precedes  the  seg- 
mentation of  the  yolk ;  this  gives  rise  to  four  pear-shaped  parts  of 
equal  size,  which  divide  towards  their  narrower  end  into  four  ecto- 
dermal and  four  endodermal  cells  ;  the  latter  are  at  first  the  larger, 
but  the  ectodermal  cells  increase  rapidly  in  size  and  form  a  cap  over 
the  others.  The  endodermal  cells,  as  they  multiply,  become  arz'anged 
in  two  rows,  and  gradually  separate  so  as  to  form  a  cavity.  The 
embryo  is  convex  on  its  dorsal  surface,  and  there  is  a  median  groove 
on  the  ventral ;  the  whole  larva  is  covered  by  cilia,  of  which  there  is 
a  large  tuft  just  in  front  of  the  eyes,  and  a  smaller  one  at  the  hinder 
end.  The  animal  at  this  stage  has  consequently  very  much  the 
appearance  of  a  Pilidium. 

Goette,  from  the  fact  that  there  are  certain  Nemertines  which  cast 
their  larval  integument,  like  Pilidium,  without  having  the  form  of  this 
larva,  and  that  there  are  Dendroccela  which  pass  through  a  Pilidium 
stage  without  undergoing  any  true  metamorphosis,  concludes  that  there 
are  various  modifications  of  this  relatively  simple  process  of  develop- 
ment, and  that  the  developmental  history  of  the  Nemertines  may  be 
referred  to  that  of  the  Dendroccela. 

Organization  and  Development  of  the  Oxynrids. — Dr.  Osman 
Galeb  made  a  communication  last  year  to  the  French  Association  for 
the  Advancement  of  Science  on  the  Oxyurids  found  as  parasites 
in  insects,  which  is  now  published  in  Professor  Lacaze-Duthiers' 
'Archives.'*  Dr.  Galeb  has  found  difierent  species  of  parasites 
in  different  species  of  insects,  notwithstanding  the  similarity  of 
habit  in  the  hosts,  and  he  draws  more  particular  attention  to  the 
mode  of  development,  and  to  the  genetic  affinities  of  these  parasitic 
forms. 

The  ova  are  easily  studied  owing  to  their  great  transparency ;  the 
germinal  vesicle  was  not  found  to  disappear  at  the  period  of  segmenta- 
tion, but  to  elongate  and  divide ;  and  indeed  it  is  not  till  after  its 
segmentation  that  the  egg  begins  to  undergo  the  same  process.  The 
enteric  tube  is  formed  by  two  swellings,  which  gradually  meet  one 
another ;  the  more  anterior  forms  the  oesophagus  and  the  commence- 
ment of  the  intestine.  The  observations  of  the  author  on  the  develop- 
ment of  the  generative  organs  do  not  agree  with  those  of  Schneider  ; 
his  later  observations  lead  to  the  conclusion  that  these  parts  are  formed 
by  the  proliferation  of  a  cell  in  the  abdominal  region,  and  not  by  the 
division  of  the  primitive  cells  into  a  central  (ovarian)  and  a  peripheral 
(investing  and  supporting)  series. 

M.  Galeb  believes  that  as  the  various  species  of  Orthoptera  and 
Coleoptera  which  he  has  studied  have  become  differentiated  from  a 
parent  form,  the  parasite  of  that  parent  form  has  likewise  become 
differentiated  into  different  species  adaj)ted  to  their  varying  hosts. 
With  regard  to  these  observations  it  may  be  interesting  to  draw 
attention  to  the  fact  that  Mr.  A.  H.  Garrod,  the  Prosector  of  the 
Zoological  Society,  has  found  a  species  of  Tcenia  in  the  Rhinoceros 
from  the  Sonderbunds,  which  he  regards  as  identical  with  the  species 
of  this  parasite  found  by  Professor  Peters  of  Berlin  and  Mr.  Garrod's 
*  '  Arch.  Zool.  Exp.  and  Gen.,'  v.  (1878). 

VOL.    II.  U 


290  NOTES   AND    MEMORANDA. 

predecessor  in  bis  office,  Dr.  Murie,  in  two  quite  distinct  species  of 
Khinoceros.* 

Researclies  on  Bonellia  viridis. — This  interesting  Gepliyrean 
genus  has  been  studied  by  F.  Vejdovsky,  who  gives  an  account  of  the 
mode  of  formation  of  the  eggs  in  the  female,  and  of  the  organization 
of  the  male.f 

1.  Formation  of  the  Ova. — The  ovary  is  attached  to  a  sort  of  peri- 
toneal fold,  and  at  its  least  developed  end  shows  small  accumulations 
of  similar  cells.  Of  these  ova  one,  enlarging  at  the  expense  of  the  others, 
becomes  the  egg-cell ;  the  sister-cells,  or  follicular  cells,  being  gradually 
compressed  and  flattened  until  they  form  a  mere  secondary  membrane 
to  the  egg,  external  to  the  vitelline  membrane.  Some  of  the  sister- 
cells,  however,  do  not  take  on  the  character  of  a  follicular  epithelium, 
but  form  a  hollow  cap  over  one  pole  of  the  egg,  outside  the  follicle ; 
these  also  gradually  dwindle  away  as  their  substance  is  absorbed  by  the 
rapidly  developing  egg-cell,  until  finally  they  vanish  altogether. 

2.  Structure  of  the  Male. — The  curious  parasitic  Turbellarium- 
like  male  of  Bonellia,  discovered  by  Kowalewsky,  was  found  by  Vej- 
dovsky in  the  oesophagus  of  young  females,  as  well  as  in  the  oviduct 
of  sexually  perfect  females,  and  in  the  mud  in  which  these  live.  It 
is  a  minute  elongated  creature,  covered  with  a  ciliated  cuticle,  and 
having  a  straight,  widish  alimentary  canal  opening  by  a  mouth  near  the 
anterior  end  of  the  body,  and  contained  in  a  body  cavity  ;  there  is  also 
an  indistinct  non-ganglionated  ventral  nerve-cord.  The  spermatozoa 
are  formed  from  cells  detached,  as  rounded  aggregations,  like  those 
from  which  the  eggs  are  produced,  from  the  peritoneal  membrane  lining 
the  body  cavity.  The  spermatozoa  pass  by  a  ciliated  funnel  into 
a  spacious  vesicula  seminalis,  which  lies  on  the  dorsal  side  of  the  ali- 
mentary canal,  and  opens  by  an  aperture  at  the  anterior  end  of  the 
body.  The  male  excretory  apparatus  thus  closely  resembles  that  of 
the  female,  in  which  there  is  a  ciliated  funnel  leading  by  a  duct  into 
a  uterus  in  which  the  eggs  are  stored,  and  which  oj^ens  externally  by 
an  oviduct.  In  both  sexes,  also,  there  is  a  pair  of  chitinous  hooks  in 
relation  with  the  genital  aperture  :  these  were  discovered  in  the  male 
by  Marion,  who  contributes  a  woodcut  illustrating  their  position  to 
Vejdovsky's  paper,  which  is  further  accompanied  by  a  plate. 

The  male  of  Bonellia  is  alsi  >  treated  of  in  a  short  paper  by  Selenka,;}: 
whose  account  differs  in  certain  important  respects  from  that  given 
above.  He  denies  the  presence  of  a  cuticle,  and  states  that  the  external 
layer  of  the  body  is  covered  by  ordinary  ciliated  cells.  He  denies 
also  the  presence  of  both  mouth  and  anus,  and  describes  the  nervous 
system  as  possessing  a  distinct  suboesophagcal  ganglion  and  circum- 
oesophageal  ring.  The  animal  also  possesses,  according  to  Selenka,  a 
pair  of  segmental  organs  in  the  hinder  third  of  the  body.  He  remarks, 
in  conclusion,  upon  the  intei'est  oi  Bonellia  as  affording  one  of  the  few 
cases  of  polyandry  known  in  the  animal  kingdom ;  four  to  twelve  or 
even  twenty  males  being  found  in  a  single  female. 

*  'Proc.  Zool.  Soc.,'  Nov.  1877. 

t  '  Zeitschr.  f.  wiss.  Zool.,'  xsx.  (1879)  487. 

i  '  Zool.  Anzeiger,'  i.  (1878)  120. 


NOTES    AND    MEMORANDA.  291 

Development  of  Chaetopoda. — The  development  of  two  species  of 
Serpula  (S.  uncinaia  and  S.  glomerata)  i.as  been  studied  by  Michael 
Stossich,*  who  sums  up  the  results  of  his  investigations  as  follows  : — 

1.  The  eggs  of  tube- worms  undergo  comi^lete  yolk-division. 

2.  From  the  blastula  a  gastrula  is  formed  by  invagination:  the 
so-called  blastopore  passes  directly  into  the  permanent  anus. 

3.  The  cleavage  cavity  (blastocele)  is  filled  with  an  albuminous 
or  fatty  fluid,  exuded  from  the  blastoderm-cells,  which  serves  the 
purpose  of  a  food-yolk. 

4.  The  inner  wall  of  the  alimentary  canal  and  the  surface  of  the 
free-swimming  larva  are  covered  with  cilia. 

5.  On  the  inner  surface  of  the  digestive  canal  are  found  two  dupli- 
catures  marking  the  boundaries  between  CESophagus,  stomach,  and 
intestine. 

6.  The  cleavage  cavity  undergoes  conversion  directly  into  the  body 
cavity,  in  which,  probably,  at  a  later  period,  the  mesoderm  cells  arise. 

7.  Above  the  anal  aperture  a  vesicle  (?)  is  formed,  which  is  con- 
nected with  the  formation  of  the  muscular  system. 

8.  Underneath  this  "  anal  vesicle  "  the  larv£e  develop,  at  the  end 
of  the  body,  a  tongue-shaped  mass,  by  means  of  which  they  attach 
themselves  to  foreign  bodies. 

Parasitism  of  Notommata  on  Vancheria.— E.  Wollny,  of  Nieder- 
lossnitz,  has  made  some  recent  observations  on  the  mode  in  which 
this  Eotifer  is  developed  within  the  Vaucheria-cell.  f  The  Vaucheria 
in  which  the  development  takes  place  is  so  weakened  as  to  be  unable 
to  produce  the  reproductive  organs ;  the  part  in  which  the  ova  are 
found  being  modified'for  the  purpose  of  forming  the  swellings  or  galls 
within  which  the  rotifer  is  developed  from  the  ovum.  The  ova  have 
the  tendency  to  force  themselves  into  the  Vaucheria-tube  through  the 
canal  which  unites  the  gall  to  the  tube,  and  do  not  escape  directly 
from  the  gall.  The  tube  either  then  decays  in  consequence  of  being 
deprived  of  nutriment,  or  the  young  rotifer  forces  its  way  through  it. 
In  a  Vaucheria  obtained  from  Kome,  Wollny  detected  also  galls  of  a 
slightly  different  character  ;  but  he  had  no  opportunity  of  examining 
either  the  ova  of  the  parasite  or  the  perfect  animal. 

Kidney  of  the  Fresh- water  Crayfish.  —  An  investigation  on  the 
curious  "  green-gland"  of  the  Crayfish  has  been  lately  made  by 
C.  E.  Wassiliew,  I  whose  observations  form  an  important  contribution 
to  our  knowledge  of  that  organ.  He  states  that  the  gland  consists  of 
a  single  unbroken  coiled  tube,  blind  at  one  end,  opening  at  the  other 
into  the  sac  of  the  gland  or  urinary  bladder,  and  consisting  of  three 
distinct  portions.  The  first  of  these  has  the  form  of  a  somewhat 
triangular  yellowish-brown  lobule,  lying  on  the  upper  surface  of  the 
gland  and  forming  the  blind  terminal  portion  of  the  whole  tube ;  the 
second  forms  a  green  cake-shaped  mass,  constituting  the  lateral  and 
inferior  parts  of  the  gland ;  while  the  third  is  a  long,  white,  coiled 

*  '  Wiener  Sitzungsb.,'  Ixxvii.  (1878)  1  Abth.  533. 
t  '  Hedwigia,'  xvii.  (1878)  5  and  97. 
X  '  Zool.  Anzeiger,'  i.  (1878). 

u  2 


292  NOTES   AND   MEMORANDA. 

tube,  connected  at  the  end  with  the  green  portion  and  by  the  other 
opening  into  the  bladder. 

The  entire  tubular  gland  is  lined  by  a  single  layer  of  epithelial 
cells,  outside  which  is  a  fine  structureless  tunica  propria,  containing 
strongly  refracting  nuclei.  There  is  no  cuticular  lining  to  the  tube, 
which  thus  differs  very  markedly  from  the  Malpighian  vessels  of  insects. 
In  the  yellow  portion  the  cells  are  sharply  defined  and  convex  on  their 
inner  surface.  In  the  green  part  of  the  tube  the  cells  are  large,  and 
their  protoplasm  is  in  connection  with  a  peculiar  network  of  pseudo- 
podial  processes  which  extend  into  projections  of  the  wall  into  the 
lumen  of  the  tube.  In  the  proximal  portion  (that  nearest  to  the  green 
section)  of  the  white  part  of  the  tube  the  walls  are  smooth,  and  lined 
by  small  cells  approaching  the  pavement  form.  In  its  distal  portion 
mammilliform  or  dendritic  processes  of  the  wall  project  into  the 
cavity,  often  giving  the  tube  a  spongy  appearance,  and  the  cells  have 
long  broad  processes  developed  from  their  inner  surfaces.  The 
epithelium  of  the  bladder  agrees  with  that  of  the  smooth  portion  of 
the  tube. 

The  products  of  secretion  are  seen  in  the  white  and  green  but  not 
in  the  yellow  portion  of  the  gland,  as  yellowish,  rather  highly 
refracting  drops  on  the  surface  of  the  cells.  Probably  the  yellow 
part  secretes  a  substance  soluble  in  alcobol.  That  part  of  the  white 
tube  with  tessclated  epithelium  most  likely  acts  merely  as  a  duct. 

The  anterior  portions  of  the  gland  and  bladder  are  supplied  by  a 
branch  of  the  antennary  arteries,  their  posterior  portions  by  the 
sternal  arteries ;  these  break  up  into  a  rich  network  of  capillaries  in 
all  parts  of  the  gland.  The  nerve  supply  of  the  bladder  is  also 
derived  from  two  sources,  its  first  part  being  sujiplied  by  a  branch  of 
antennary  nerves  (coming  from  the  supra-oesophageal  ganglion),  its 
hinder  part  by  a  nerve  from  the  infra-oisophageal  ganglion.  No  nerves 
were  observed  in  the  gland  itself. 

Action  of  the  Heart  of  the  Crayfish.  —  M.  Felix  Plateau,  of 
Ghent,  has  succeeded  in  applying  the  graphic  method  to  the  study  of 
the  heart's  action  in  the  crayfish.  A  curve  is  obtained,  of  which  the 
ascending  portions  correspond  to  diastole,  and  the  descending  to 
systole,  contrary  to  what  obtains  in  the  Vertebrate  heart.  It  is 
strikingly  like  the  trace  of  the  contraction  of  a  muscle  ;  a  rapid, 
almost  sudden  ascent,  with  a  short  flat  summit,  then  a  gradual  de- 
scent, at  first  quicker,  then  slower.  This,  however,  does  not  represent 
the  whole  truth  ;  it  is  possible  also  to  demonstrate  a  wave  affecting 
the  muscular  wall  of  the  heart,  and  travelling  from  behind  forwards, 
thus  demonstrating  that  this  condensed  heart  is  a  true  dorsal  vessel. 
On  the  stimulus  of  the  entrance  of  renovated  blood,  it  is  only  the 
hinder  half  or  two-thirds  of  the  heart  that  contracts  immediately. 
This  forces  blood  into  the  forward  half,  which  contracts  only  when 
the  posterior  division  is  again  dilating.  When  the  temperature  is 
increased,  as  a  general  rule  the  diastolic  jDhase  is  abbreviated,  the 
number  of  pulsations  rising  at  the  same  time.  M.  Plateau  has  also 
succeeded  in  making  experiments  on  the  action  of  the  cardiac  nerve 
of  Lemoine,  an  unpaired  branch  of  the  stomatogastric  ganglion.     It 


NOTES   AND   MEMORANDA.  293 

is  proved  that  excitation  of  this  nerve  quickens  the  pulsations  of  the 
heart  and  augments  their  energy,  while  section  of  it  slows  the  heart. 
Excitation  of  the  thoracic  ganglia  always  retards  the  heart,  the  con- 
verse of  the  cardiac  nerve.  Acetic  acid  applied  to  the  heart  substance 
arouses  its  contractions  even  when  they  have  ceased,  and  maintains 
them  for  several  hours. 

The  action  of  a  number  of  other  substances  is  equally  noteworthy, 
and  M.  Plateau's  full  communications  to  the  Academie  Eoyale  of 
Belgium  will  be  awaited  with  interest  by  physiologists.* 

Natural  Classification  of  the  Spiders. — Dr.  Bertkau  points  out  f 
the  great  difficulty  of  classifying  the  group  ;  comparing  them  with  the 
Insecta  (Hexapoda),  he  says  that  the  body  is  only  divided  into  two 
regions,  that  there  are  no  antennae  or  wings  to  aid  in  discrimination, 
and  that  even  those  parts,  which  vary  in  other  Arthropoda,  present  iu 
tbera  a  remarkable  uniformity  ;  thus  there  are  almost  always  eight 
eyes,  and  a  variation  in  the  number  of  these  is  of  doubtful  value,  the 
mouth-organs  are  always  of  the  same  structure,  and  the  number  of 
joints  in  the  legs  is  very  fairly  constant ;  nor  do  the  spinning  warts 
afford  any  greater  aid.  Turning  to  the  variations  in  their  habits,  he 
observes  that  Aristotle,  just  as  much  as  the  latest  systematists,  drew 
attention  to  the  difference  in  the  characters  of  the  web,  and  of  the 
methods  by  which  these  creatures  obtain  their  prey,  but  these  differ- 
ences are  of  no  value  as  aids  to  classification  from  a  morphological 
point  of  view. 

In  the  present  essay  an  attempt  is  made  to  take  into  account  all 
the  variations  in  organization,  and  to  use  only  the  characters  of  the 
web  as  a  last  resource,  for  the  very  excellent  reason  that  these  are  of 
no  assistance  in  the  classification  of  dead  Spiders.  The  following  is  a 
short  outline  of  the  grouping  here  proposed  : — 

Sub-order  I. —  Tetrasticta ;  two  pairs  of  stigmata  on  the  lower 
surface  of  the  abdomen ;  ovaries  and  testes  circular,  the  entrance  to 
the  seminal  pouches  simple,  and  just  in  front  of  the  orifice  of  the 
oviduct. 

i.  Atypidce ;  with  eight  eyes,  all  four  stigmata  leading  to  the 
"lungs";  six  spinning  warts,  the  anterior  pair  short,  and  consisting  of 
one  joint ;  mandibles  horizontal  in  direction  ;  more  than  one  recepta- 
culum  seminis. 

ii.  Di/sderidcB ;  with  six  eyes,  the  two  hinder  stigmata  leading 
into  a  tracheal  system ;  the  six  spinning  warts  sub-equal,  and  all 
consisting  of  one  joint  each  ;  mandibles  vertical,  or  directed  obliquely 
forwards  ;  only  one  receptaculum  seminis. 

II.  Trisdcta. — Only  one  pair  of  stigmata  on  the  lower  surface  of 
the  abdomen ;  ovaries  and  testes  in  two  branches ;  there  are  ordinarily 
two  openings  into  the  seminal  pouches. 

These  are  divided  into  nineteen  families,  many  of  which  have 
well-known  names,  though  their  limits  are  in  most  cases  revised ; 
their  relations  to  one  another  are  exhibited  in  a  genealogical  tree. 

The  author  considers  that  the  Tetrasticta  are  the  more  primitive 

*  '  Nature,'  xix.  (1879)  470. 

t  '  Arch,  fiir  Naturgeechichte,'  xUt.  (1878)  351. 


294  NOTES   AND    MEMORANDA. 

forms,  basing  this  cliiefly  on  the  presence  of  two  pairs  of  stigmata, 
and  the  simplicity  of  the  male  copulatory  organs ;  palaeontology, 
however,  aflbrcls  some  support  to  his  views,  inasmuch  as  Protolycosa 
belongs  to  this  group.  With  regard  to  this  fossil  form,  Bertkau  sug- 
gests that  the  backwardly  directed  spinous  processes  found  on  the 
right  side  represent  the  hinder  pair  of  spinning  warts,  and  that  the 
small  spines  on  them  are  the  spinning  tubes. 

Researches  into  the  Developmental  History  of  the  Spiders  — 
Tlie  indefatigable  Barrois  has  a  preliminary  chapter  on  this  subject 
in  M.  Robin's  Journal.*  The  chief  aim  of  the  author  was  to  examine 
the  arrangement  of  the  germinal  layers,  and  the  mode  of  develop- 
ment of  the  internal  organs ;  this  work,  which  has  never  yet  been 
undertaken,  was  effected  by  the  aid  of  fresh  ova,  and  of  sections 
stained  by  bichromate  of  potash  and  osmic  acid.  Passing  by  some 
remarks  on  the  relative  value  of  the  observations  of  Balbiani  and  of 
Ludwig,  in  which  attention  is  drawn  to  the  highly  granular  character 
of  the  protoplasm  of  the  formative  layer,  we  note  that  Barrois 
adds  something  to  the  observations  made  by  Claparede  on  the  primitive 
streak ;  the  latter  admirable  student  had  noted  the  appearance  of 
thoracic,  abdominal,  and  post-abdominal  zonites,  but  he  did  not  note  the 
presence  of  two  cords,  formed  of  several  rows  of  embryonic  cells  ;  to 
these  Barrois  gives  the  name  of  germinal  hands  ;  they  are  derived  from 
a  primitively  continuous  mesodermal  layer,  and  are  found  throughout 
the  whole  length  of  the  body,  although  they  are  largest  in  the  thoracic 
region ;  in  this  they  may  be  seen  to  be  dividing  into  a  median 
(nervous)  and  a  peripheral  portion ;  more  anteriorly,  they  form  the 
cerebral  lobes  (procephalic  lobes  of  Claparede  and  Huxley) ;  on  the 
whole  this  region  is,  at  this  period,  strikingly  like  the  same  parts  in 
the  Scorpions,  the  development  of  which  have  been  already  described 
by  Metschnikoff.  Behind  the  thoracic  region  there  are  ordinarily  ten 
zonites,  of  which  the  first  four  are  provided  with  the  rudiments  of 
appendages. 

By  following  out  the  stages  of  development  step  by  step,  Barrois 
has  been  enabled  to  discover  a  stage — to  which  he  applies  the  term 
Limuloid — which  was  not  observed  by  Claparede.  In  this  state  the 
embryo  has  an  exceedingly  remarkable  appearance ;  it  is  divided  into 
two  distinct  parts,  thoracic  and  abdominal ;  the  posterior  portion  is 
formed  by  the  fusion  of  all  the  tergal  arcs,  in  which,  however,  it  is 
possible  to  observe  a  jire-abdomen,  consisting  of  six,  and  a  post-abdo- 
men, consisting  of  four  segments.  Of  the  former  series  four  are 
larger  than  the  other  two,  and  are  seen  to  be  provided  with  appendages  ; 
the  anal  segment,  if  examined  from  its  ventral  surface,  is  found  to  be 
made  up  of  three  segments,  so  that  there  are  altogetlier  twelve  seg- 
ments in  the  abdomen,  or  six  in  the  post-abdomen,  and  the  number  of 
these  in  the  Spiders  is  found  to  correspond  with  those  of  the  same 
region  in  the  Scorpions.  In  one  of  the  Xiphosura,  Hemiaspis  limu- 
loidcs,  the  arrangement  of  parts  is  strikingly  similar  to  what  is  here 
observed  in  the  embryo  of  the  Spider ;  the   higher  development  of 

*  '  Journ.  Anat.  Thys.,'  xiv.  (1878)  527. 


NOTES   AND   MEMORANDA.  295 

the  first  four  abdominal  segments  appears  to  be  a  constant  phenomenon 
in  the  Arachnida  ;  in  explanation  of  this  it  may  be  observed  that 
these  segments  appear  together  and  before  those  that  succeed  them, 
and  that  the  pame  remark  applies  to  the  ganglia  that  innervate  them. 
The  vitelline  portions  of  the  egg  are  also  of  great  interest ;  the  "  vitel- 
line vesicle  "  forms  a  sac  on  the  ventral  surface,  just  as  in  Fishes,  and 
as  in  them  it  owes  its  existence  to  the  presence  of  too  much  yolk ; 
Barrels  believes  that  attention  is  now  for  the  first  time  drawn  to  the 
presence  of  this  body  in  any  Invertebrate.  The  succeeding  stages  are 
too  briefly  indicated  for  us  to  bo  able  to  give  any  shorter  account  of 
them  ;  there  are  a  number  of  figures  in  illustration. 

New  Genus  of  the  Cheliferidae.— M.  E.  Simon  has  found  *  that 
many  of  the  forms  of  this  group  which  came  to  hand  are  not  indigenous 
to  the  French  fauna ;  the  one  now  to  be  mentioned  was  found  in  a 
chest  containing  some  Japanese  objects,  and  is  eliminated  by  M.  Simon 
from  the  "  Arachnides  de  France,"  of  v»'hich  he  is  preparing  a  mono- 
graph. The  name  Lopliochernes  (hicarinatus)  is  given  to  it ;  it  has 
most  of  the  characters  of  Chelifer,  but  the  second  cephalothoracic 
groove  is  much  deeper  than  the  first ;  the  first  five  abdominal  segments 
are  strongly  carinated  at  the  sides,  which  is  not  the  case  with  those 
that  succeed  them.  The  movable  portion  of  the  chelae  is  strongly 
curved,  and  only  touches  the  fixed  part  by  its  tip  when  the  pincer 
is  closed. 

New  Acarina. — Dr.  Kramer  points  out  f  that  the  observation  of 
Claparede  as  to  the  enormous  number  of  these  forms  is  confirmed  by 
every  new  series  of  observations ;  these  forms  are  moreover  most 
remarkable,  while  they  never  lose  the  characters  common  to  their 
family ;  the  divergencies  seen  in  them  cannot  be  explained  as  due  to 
different  habits  of  existence,  and  as  yet  comparative  embryology  has 
been  able  to  throw  but  little  light  on  the  question.  The  true  natu- 
ralist must,  therefore,  content  himself  for  the  present  by  bringing 
together  the  material  which  shall  aid  later  observers  in  giving  a  more 
general  review  of  the  group.  With  this  object  in  view  he  pro- 
ceeds to  deal  with  some  new  forms ;  two  new  genera,  Labidostoma 
and  Gustavia,  and  six  species  of  already  known  genera  are  described. 

Crganization  of  Myriapoda. — The  Myriapoda  collected  in  Tur- 
kestan by  Fedtschenko  have  been  examined  by  N.  Sograff  of  Moscow, 
who  gives  in  the  '  Zoologischer  Anzeiger '  a  preliminary  account  of 
the  chief  results  he  has  obtained. | 

1.  On  the  under  side  of  the  head  of  Chilopoda  occur  a  quantity 
of  chitinous  plates,  which  are  not  of  a  segmental  nature,  but  are  mere 
cuticular  thickenings  (sclerites)  serving  for  the  attachment  of  muscles. 

2.  The  alimentary  canal  is  lined  with  very  peculiar  epithelial 
cells  of  two  kinds  ;  the  first  are  long  and  fine,  and  bear  more  resem- 
blance to  the  olfactory  cells  of  Vertebrates  than  to  the  cells  usually 
found  in  the  gut  of  Arthropods ;  the  second  kind  are  oval  or  rounded, 

*  'Bull.  Soc.  Zool.  de  France,'  iii.  (1878)  66. 
t  'Arch,  fiir  Naturgeschichte,'  xlv.  (1879)  1. 
%  '  Zool.  Anzeiger,'  ii.  (1879)  16. 


296  NOTES   AND    MEMOBANDA. 

and  contain  brown  granules :  the  rectum  is  also  lined  witli  a  charac- 
teristic epithelium. 

3.  The  circulatory  system  consists  of  a  very  narrow  dorsal  vessel, 
the  walls  of  which  are  composed  of  annular  striated  muscles;  the 
alary  muscles  appear  to  exist  only  in  Scolopendra. 

4.  The  tracheje  agree  in  their  disposition  and  external  appearance 
with  those  of  the  larvse  of  insects  (Lepidoptera),  the  stigmata  are 
provided  with  a  simple  but  very  characteristic  valvular  apparatus.  '3  ^5 

5.  Thebrainconsistsof  fibres,  and  of  cells  of  two  kinds.  The  fibres 
have  a  reticulated  arrangement  in  the  interior  ;  the  cells  of  the  first 
kind  are  large,  and  uni-,  bi-,  or  tripolar :  those  of  the  second  kind 
are  much  smaller,  round  or  elliptical,  and  correspond  to  the  cerebral 
granules  (Hirnkernen)  of  Dietl.  The  form  of  the  brain  is  correlated 
with  the  number  of  eyes  and  with  the  length  of  the  body ;  the  longer 
the  body  of  the  Chilopod,  the  fewer  are  its  eyes,  and  the  smaller  its 
optic  lobes.     The  latter  are  wholly  absent  in  the  Himantaria. 

6.  The  structure  of  the  eye  resembles  that  of  insect  larvae.  The 
eyes  of  the  Lithobii  and  Scolopendrce  are  quite  like  those  of  the  larva 
of  Acilius,  &c.,  or  those  of  Sj^iders.  The  compound  eye  of  Cermatia 
consists  of  a  number  of  lesser  eyes,  closely  resembling  those  of  the 
larvfe  of  Hymenoptera.  The  optic  lobes  terminate  in  a  small  nerve, 
the  branches  of  which  go  to  the  separate  eyes. 

7.  The  genital  organs  are  very  peculiar  with  regard  both  to  their 
external  and  internal  structure.  The  ovary  agrees  closely  in  structure 
with  that  of  Araclinida.  The  eggs  are  disposed  in  grape-like  bunches, 
the  ripe  ones  being  covered  with  a  layer  of  cells,  probably  epithelial. 
The  recepticula  seminis  exhibit  epithelial  and  muscular  layers.  The 
testis  is  filled  with  large  quadrangular  mother-cells  with  large  nuclei, 
probably  derived  from  the  epithelium  of  the  thin  upper  part  of  the 
gland.  Its  walls  are  invested  with  strong  muscular  bundles  and  a 
layer  of  nuclei.  The  walls  of  the  vesicula  seminalis  consist  of  an 
epithelial  layer  and  of  a  delicate  network  of  muscles. 

8.  Glands  occur  in  great  numbers  in  the  mouth,  in  the  thorax,  on 
the  outer  surface  of  the  body,  and  on  the  appendages.  The  pores  on 
the  coxfe  (Coxalporen)  are  also  glandular.  The  duct  of  the  poison 
gland  is  a  strong  chitinous  canal  with  small  tubules  of  the  same 
material  opening  into  it ;  each  of  these  tubules  terminates  in  a  pear- 
shaped  gland-lobule.  The  whole  gland-system  is  covered  with  a 
characteristic  layer  of  muscular  fibres  :  so  also  is  the  nervous  system. 

9.  The  organization  of  the  short  Chilopods  with  comparatively 
few  legs  {Lithohius,  Cermatia,  Scolopendra)  is  higher  than  that  of  the 
long  Geophili  and  Himantaria. 

10.  Of  the  other  Arthropoda  the  Chilopoda  are  most  nearly  related 
to  the  larvae  of  Lepidoptera,  Hymenoptera,  and  Coleoptera. 

Polyxenus  lagurus,  De  Gear. — Haller  makes  some  remarks  *  on 
this  curious  little  Myriapod,  which  he  got  from  under  the  bark  of  old 
cherry-trees,  though  never  in  brushwood  or  hedges  ;  he  draws  attention 
to  the  structures  found  in  the  caudal  appendages  of  these  animals,  and 

*  '  Arch,  fiir  Naturgeschichte,'  xliv.  (1878)  91. 


NOTES   AND    MEMORANDA,  297 

points  out  how  closely  they  resemble  in  form  the  siliceous  spicules  of 
various  Sponges.  He  has  observed  how  greatly  these  are  in  the  power 
of  the  small  spiders  that  live  with  them,  and  which  are  able  to  para- 
lyze their  action  although  not  able  to  destroy  them. 

Parthenogenesis  in  Bees. — MM.  Perez  and  Sanson  have  each  an 
article  in  the  last  number  of  the  '  Annales  des  Sciences  Naturelles ' 
(Zool.),*  in  which  they  repeat  and  confirm  the  views  already  expressed 
on  this  subject.     See  p.  88  of  this  Journal. 

Spinning  Glands  of  the  Silkworm. — Each  of  the  two  spinning 
glands  Professor  Lidth  de  Jeude  describes  f  as  consisting  of  three 
parts  ;  a  thin-walled  efferent  duct,  a  thick  and  slightly  coiled  reservoir, 
and  a  long  and  greatly  coiled  hinder  pjrtion.  In  all  three  it  is  pos- 
sible to  make  out  a  thin  and  homogeneous  membrana  propria,  and  a 
unicellular  layer  of  pavement-epithelium ;  at  the  commencement  of 
the  median  portion  of  the  glandular  region  there  is  also  a  firm  cuti- 
cular  intima.  The  tunica  projpria  is  traversed  by  tracheal  ramules  in 
the  median  and  hinder  portion  of  the  gland,  and  numerous  branches 
of  these  pass  into  and  between  the  epithelial  cells  ;  each  of  these  cells 
contains  several  twigs.  The  cells  of  the  glandular  epithelium  differ 
in  character  in  each  of  the  three  regions,  but  they  all  agree  in  dis- 
playing the  absence  of  a  distinct  membrane,  the  presence  of  large 
stellate  nuclei,  and  a  colourless  protojilasm.  The  largest  and  flattest 
cells  are  found  in  the  median,  and  the  smallest  in  the  anterior  part. 

With  regard  to  the  efferent  duct,  it  is  noted  that  the  protoplasm  of 
its  cells  consists  of  closely  approximated  doubly-refracting  fibrillte  set 
in  a  singly  refracting  substance ;  they  are  placed  at  right  angles  to 
the  axis  of  the  canal  and  give  the  micro-chemical  reactions  of  albumen. 
The  protoplasm  is  separated  from  the  intima  by  a  transparent,  singly 
refracting  layer,  which  is  traversed  by  pore-canals  ;  this  layer  is 
easily  broken  up  by  treatment  with  alkaline  reagents. 

The  intima,  which  is  about  y^®  q  ^™*  thick,  is  of  a  yellowish-brown 
colour,  is  very  firm,  elastic,  and  doubly  refracting ;  it  is  fibrous  in 
structure,  but  the  fibres  are  not  destroyed  by  alkalies.  The  lumen  of 
the  efferent  duct  is  filled  by  a  colourless  fluid,  and  the  filaments  found 
in  it  are  highly  refracting  and  are  anisotropic.  The  protoplasm  of 
the  cells  of  the  median  portion  is  finely  granular,  and  is  not  aniso- 
tropic ;  it  differs  in  character  in  different  regions ;  the  fibres  which 
are  found  at  the  periphery  of  the  tube  are  also  essentially  protoplasmic 
in  character,  and  are  not  chitinized.  The  very  wide  portion  of  the 
median  region  is  in  the  posterior  portion  completely  filled  by  the  highly 
refractive  and  viscid  secretion  which  is  found  in  it,  and  which  goes  to 
form  the  silk-threads. 

The  cellular  protoplasm  of  the  hinder  portion  of  the  gland  is 
granular,  and  consists  of  irregularly  prismatic  bodies;  the  cell- 
substance  is,  when  dried,  highly  refractive. 

The  following  are  the  more  important  physiological  results  re- 
corded by  the  author :  When  living  glands  were  electrically  irritated, 

*  Vol.  vii.  (1879).  t  'Zool.  Anzeiger,'  i.  (1878)  100. 


298  NOTES   AND    MEMORANDA. 

the  contents  of  the  glands  were  expelled  with  greater  rapidity ; 
totauization  had  a  more  marked  effect,  and  produced  changes  in  the 
characters  of  the  cells  ;  the  most  imjiortant  of  the  chemical  elements 
found  in  the  fully  formed  silk-thread  was  fibrous ;  the  yellow  colour- 
ing matter  was  observed  to  be  formed  in  the  cells  of  the  median 
portion,  and  it  was  also  noted  that  the  silk-threads  did  not  exhibit 
their  special  characters,  or  power  of  refracting  light,  unless  they 
were  taken  from  the  region  in  which  the  two  efferent  ducts  were 
found  united. 

Odoriferous  Cells  in  Lepidoptera.  —  The  observations  of  Fritz 
Miillcr  on  the  attractive  proi)erties  possessed  by  the  males  of  certain 
LepidojDtera  revealed  the  jireseuce  of  certain  cells  which  seemed  to 
give  off  an  odorous  oil  of  the  ether  series ;  the  scaly  cells  to  which 
this  oil  owed  its  existence  were  never,  however,  found  on  the  costce, 
where,  as  it  was  imagined,  the  living  cells  of  the  wings  were  alone  found. 
Dr.  August  Weissmann  now  *  points  out  that  this  last  supposition  is 
erroneous,  and  that  the  other  cells  of  the  wing  form  a  connected 
network  of  irregularly-branched  stellate  cells,  which  are  placed  in 
more  or  less  closely  set  transverse  rows  below  the  scales,  though  they 
can  only  be  made  out  by  the  use  of  reagents. 

The  scale  itself  is  capillifoi-m,  and  traversed  by  a  single  axial 
canal,  which  ojiens  freely  at  the  tip  (as  in  Pajnlis  protesilaus),  or  there 
are  a  number  of  canals,  which  open  on  to  the  surface  of  the  scale.  It 
is  in  the  butterflic^s  of  Brazil  or  the  Tropics  that  the  odoriferous  cells 
are  best  developed,  although  indeed  in  Pieris  napi  it  is  quite  easy  to 
convince  oneself  that  the  odour  is  given  oft'  from  the  scales,  by  passing 
the  finger  over  the  wing  ;  the  finger  will  be  found  to  retain  a  strong 
odour,  not  unlike  that  of  citrons.  In  the  closely  allied  species,  P.  rapce, 
the  same  may  be  observed,  but  in  it  the  odour  is  less  strong  and  of  a 
different  character. 

In  connection  with  these  observations  of  Weissmann,  we  may  draw 
attention  to  the  communication  which  Fritz  Miiller  has  made  to  his 
bruther  Hermann  ;  |  he  says  that  he  finds  his  nose  gets  sharper  in 
detecting  odours  from  butterflies  ;  thus,  the  male  of  Callidryas  trite 
was  two  years  ago  odourless,  but  he  is  now  easily  able  to  detect  its 
odour.  In  the  male  of  Didonis  hiblis  he  has  now  observed  three 
distinct  odours  in  different  parts.  The  females  of  Callidryas  have 
highly  odorous  glands  connected  with  their  generative  organs,  which 
give  off  an  acetous  scent ;  while  the  males  of  the  same  form  have  a 
musk-like  odour  from  the  same  parts. 

Seasonal  Dimorphism  of  Lepidoptera. — Dr.  Kramer  makes  some 
elaborate  computations  J  as  to  the  modes  by  which  this  dimorphism, 
the  phenomena  of  which  have  been  so  learnedly  treated  by  Professor 
Weissmann,  have  been  evolved ;  a  severely  mathematical  study  leads 
him  to  the  following  conclusions  : — - 

1.  By   the  cumulative  action    of  transmission  (heredity)  a  large 

*  '  Zool.  Anzeiger,'  i.  (1S7S)  98.  t  Ibid.,  32. 

X  'Arch,  fiir  Natnrgeschichte,'  xliv.  (1878)  411. 


K0TE8   AND    MEMOEANDA.  299 

number  of  animal  groups  have  been  derived  from  tlio  same  species, 
and  exhibit  various  grades  of  variation. 

2.  Those  groups  which  are  most  and  those  which  are  least  altered 
are  the  less  numerous,  while  those  which  have  undergone  the  mean 
amount  of  variation  are  the  most  numerous. 

3.  The  series  of  variations  is  an  unbi'uken  one. 

4.  These  variations  are  not  affected  by  any  length  of  time. 
Development  of  Podurella. — There  is  a  short  note  in  the  '  Eevue 

Internationale  des  Sciences,'  vol.  ii.  p.  439,  on  the  investigations  of 
Barrois.  In  the  anterior  region  the  sternal  arcs  are  found  to  be,  as  in 
other  insects,  the  first  formed,  and  to  be  developed  from  below  U2)wards  ; 
the  cephalic  lobes,  the  antennsB,  and  the  labnun  can  soon  be  made  out 
in  the  cephalic  region ;  then  follows  the  mouth,  then  six  pairs  of 
limbs,  of  which  the  first  three  go  to  form  the  labrum  and  the  mouth- 
organs,  while  the  other  three  develop  into  the  thoracic  limbs. 

In  the  abdominal  region,  it  is  very  different ;  the  tergal  arcs  are 
the  first  to  be  formed,  and  development  takes  place  in  a  dorso- 
ventral  direction  ;  in  this  stage  the  insect  is  said  to  have  no  slight 
I'Bsemblance  to  the  Zoea  form  of  the  Crustacea. 

Respiratory  Organs  of  the  Larva  of  Culex. — These  are  seen  by 
Dr.  G.  Haller  *  to  be  excellent  examples  of  an  intermediate  stao^e 
between  the  arrangements  found  in  the  larvae  of  the  Phryganida  and 
of  the  Ephemerida  on  the  one  hand,  and  in  such  adult  forms  as  ^cjm 
or  Banatra  on  the  other. 

Two  well-developed  longitudinal  trunks  extend  through  the 
whole  body,  and  supply  all  its  parts  with  air ;  they  are  extremely 
delicate,  and  are  provided  with  a  fine  spiral  band  of  chitiu ;  just 
before  reaching  the  cephalic  segment  they  turn  inwards  at  a  right 
angle  ;  at  this  point  there  is  developed  a  contractile  vesicle,  to  which 
the  older  observers  gave  the  epithet  "  respiratory  " ;  examination  of 
its  structure  reveals,  however,  its  essentially  glandular  character 
and  proves  that  it  is  connected  with  a  cellular  cord  placed  in  the 
cephalic  region.  So  far  as  is  known,  these  creatures  are  not  provided 
with  any  salivary  glands,  but  the  organ  in  question  greatly  resembles 
one.  In  the  terminal  segment  of  the  body  the  tubes  pass  towards  the 
middle  line,  and  form  respiratory  tubes,  placed  one  above  the  other  • 
the  author  distinctly  affirms  that  they  do  not  unite,  and  that  they  even 
open  separately ;  above  these  openings  there  are  three  sharp,  projecting, 
-points,  which  are  capable  of  being  closed,  and  of  thus  forming  a  kind 
of  valvular  projection  against  the  entrance  of  water  or  other  fluids. 
So  long  as  the  animal  remains  at  the  surface,  these  tubes  are  freely 
open  to  the  atmosphere ;  but  when  it  is  forced  to  descend  into  the 
water,  the  tracheal  gills,  now  to  be  described,  come  into  fimction. 
These  gills  have  the  form  of  delicate  elongated  lamellfe,  in  which  the 
terminal  branches  of  the  tracheae  are  found  to  ramify ;  they  are  placed 
on  the  opposite  surface  of  the  body  to  the  respiratory  tubes,  and  are 
provided  with  long  branched  hairs,  of  which  there  are  generally  eleven. 
Where  the  branches  that  supply  the  tracheal  gills  are  connected 
with  the  longitudinal  and  primary  air-vessels,  an  air-reservoir  is  deve- 
*  'Arch,  fill-  Natiirgf&chk'htc,'  xKv.  (1878)  91. 


300  NOTES    AKD    MEMOEANDA. 

loped  ;  tliese  consist  of  one  or  more  tufts  of  a  large  number  of  short 
ramules ;  their  function  appears  to  be  to  supply  the  organism  with  air 
during  such  short  periods  as  those  in  which  respiration  is  prevented 
or  retarded  ;  the  hairs  are  better  developed  on  the  side  nearer  to  the 
respiratory  tubes  than  on  the  other.  Very  much  the  same  relation  of 
parts  is  found  to  obtain  in  the  pupa. 

In  the  imago  the  conditions  appear  to  be  altogether  different ;  the 
insect  now  respires  by  the  aid  of  stigmata.  The  hairs  on  these  struc- 
tures are  described  in  some  detail,  and  the  descriptions  illustrated. 

Sucking  Plate  of  Dytiscus. — The  same  author  describes  *  the  chiti- 
nous  organs  on  the  sucking  plate  on  the  first  pair  of  feet  in  the  males 
of  Dytiscus.  These,  wLich  aj^pear  to  be  of  aid  in  copulation,  are 
formed  by  the  differentiation  of  the  first  joints ;  in  coi^ulation  they 
are  apjilied  to  a  shallow  groove  on  the  thorax  of  the  female  ;  they  are 
cordiform  in  shape,  and  are  formed  from  throe  of  the  joints  of  the 
tarsus ;  in  colour  they  are  more  or  less  red  or  brown,  and  on  their 
upper  surface  they  present  a  roughened,  file-like  surface,  which  is 
pi'oduced  by  the  presence  of  a  number  of  rounded,  flattened  organs, 
some  of  which  may  be  easily  perceived  by  the  naked  eye.  In  some, 
the  structure  is  remarkable  on  account  of  the  presence  of  radiating, 
yellowish,  and  branching  chitinous  hairs,  separated  by  a  colourless 
transparent  membrane,  which  is  more  or  less  distinctly  striated ;  on 
the  inner  surface  of  these  organs  there  are  roimded  bodies  which 
produce  a  dark  brown  secretion,  the  function  of  which  appears  to  be 
to  protect  the  bodies  in  question  against  the  action  of  water.  In 
others  there  are  several  transverse  rows  of  smaller  bodies ;  these 
consist  of  a  single  hollow  chitinous  hair,  which  is  closed  at  its  tip ; 
this  again  is  jirovided  with  a  transparent  chitinous  membrane  of  a 
brownish  hue.  Adding  together  all  the  prehensile  structures  observed 
on  these  appendages,  the  author  comes  to  the  conclusion  that  there  are 
no  less  than  four  hundred  of  them,  the  power  of  which  is  at  once 
apparent.  The  plates  now  described  are  provided  with  a  number  of 
hairs  of  two  kinds ;  in  one  they  are  long,  firm,  blunt,  and  curved  a 
little  inwards,  so  as  to  afford  a  protection  for  the  subjacent  struc- 
tures ;  the  others  are  broad  and  short,  are  distinctly  striated  in  a 
longitudinal  direction,  and  are  inserted  into  strong  chitinous  rings. 

Development  of  Polyzoa. — M.  W.  Eepiachoff,  of  Odessa,  has 
studied  the  development  of  Tendra  zostericola,^  of  Lepralia  palla- 
siana,  and  of  two  sj)ecies  of  BoioerhanJcia.^  In  Tendra  complete  yolk- 
division  takes  place,  and  an  equal-celled  mulberry-mass  (archimorula) 
is  produced,  which  soon  becomes  hollow  by  the  formation  of  a 
cleavage  cavity,  producing  a  one-layered  archiblastula.  Four  cells 
lying  together  in  the  centre  of  the  ventral  side,  then  enlarge  greatly, 
and  undergo  extensive  division,  forming  a  mass  of  cells  projecting 
into  the  cleavage  cavity.  This  mass  is  the  endoderm ;  its  cells  soon 
separate  from  one  another,  forming  a  cavity,  the  archenteron,  which  is 

*  'Arch.  f.  Naturgeschichtc,'  xliv.  (1878)  9]. 

t  '  Zeitsch.  f.  wiss.  Zool.,'  vol.  xxx.  Suppl.  (1878)  411. 

X  '  Zool.  Anzeiger,'  i.  (187S). 


NOTES   AND    MEMORANDA.  301 

at  first  quite  closed,  but  afterwards  opens  on  the  exterior  by  a  blasto- 
pore, produced  by  the  separation  of  those  endodermal  cells  which 
occupy  the  position  of  the  four  cells  originally  iuvaginated,  on  the 
ventral  surface  of  the  embryo.  At  a  still  later  stage  the  blastopore 
thus  formed  closes  up,  both  mouth  and  anus  being  subsequently 
formed  as  invaginations  of  the  ectoderm. 

The  chief  fact  about  Lepralia  is  the  confirmation  of  the  author's 
previously  expressed  opinion  that  the  structure  called  "  stomach  "  by 
Barrels  is  really  a  sucker. 

The  two  Bowerbankia-lsLTVse  were  pear-shaped,  with  a  mantle 
covering  the  dorsal  and  ventral  surfaces,  and  a  mantle-cavity  opening 
by  an  aperture  at  the  small  end  of  the  embryo.  The  larger  specimen 
had  on  its  flattened  ventral  side  an  elongated  ciliated  aperture,  in 
relation  with  which,  in  the  interior  of  the  body,  was  a  granular  mass 
representing  the  endoderm.  On  the  ventral  side  of  both  was  a  longi- 
tudinal groove,  bounded  by  two  folds,  and  resembling  the  medullary 
groove  of  a  Vertebrate.  In  the  smaller  specimen  this  was  continuous 
along  the  whole  ventral  side ;  in  the  larger  it  was  interrupted  by  the 
ciKated  aperture  just  mentioned. 

In  both  larvaj  there  was  a  shallow  annular  constriction  round  the 
middle  of  the  body,  and,  at  the  same  place,  a  thickening  of  the  mantle. 
A  second  constriction,  with  a  corresponding  thickening  of  the  mantle, 
occurred  between  the  first,  and  the  thin  end  of  the  body.  Corre- 
sponding to  these  constrictions,  there  was,  in  the  smaller  larva,  a 
weak  indication  of  segmentation  of  the  ventral  (supposed  medullary) 
folds. 

The  early  stages  of  develop:nent  in  the  Ctenostomata  (the  group 
to  which  Bowerbaukia  belongs)  resemble  in  a  general  way  those  of 
Tendra,  but  the  gastrula  approaches  more  nearly  to  the  simple  archi- 
gastrula. 

In  a  further  communication  Repiachoff  *  has  studied  more  care- 
fully the  later  developmental  stages  of  Tendra,  of  which  only  a  brief 
account  was  given  in  his  former  paper.  He  states  that  he  has  proved 
the  sucker  of  the  embryo  ("  stomach,"  Barrois)  to  originate  as  a 
thickening  of  the  ectoderm  on  the  ventral  side  of  the  body.  He  also 
describes  the  blind  endodermal  sac  or  midgut  of  the  embryo  as 
extending  uninterruptedly  quite  to  the  upper  end  of  the  body ;  above, 
therefore,  the  involution  which  becomes  the  foregut.  Subsequently 
this  ujiper  portion  of  the  endoderm  becomes  scjjarated  from  the 
remainder,  and  forms  a  mere  accumulation  of  cells  in  close  proximity 
to  the  oral  furrow.  The  remainder  of  the  endodermal  sac  fuses  with 
the  foregut  involution,  and  forms  with  it  a  semi-lunar  alimentary 
canal. 

Presence  of  a  Segmental  Organ  in  the  Endoproct  Polyzoa. — In 

October,  1877,  Hatschek  of  Prague  discovered  in  Pedicellina  ecldnata, 
both  in  the  larval  and  adult  state,  a  vibratile  canal  which  he 
apparently  could  not  quite  make  out,  and  which  he  compared  to  the 
vibratile   organs   of  the    Eotatoria.     M.    L.    Joliet    has  confirmed  t 

*  '  Zool.  Anzeigcr,'  ii.  (1879)  68. 

t  'Cuniptes  Pieudus,'  Ixxsviii.  (1879). 


302  NOTES    AND    MEMORANDA. 

these  observations,  and  extonded  them  to  the  whole  gi'oup  of  Eudo- 
proct  Polyzoa. 

In  some  Pedicellhice  which  he  observed  the  vibratile  organ  was 
double,  and  situated  in  the  cavity  of  the  body  in  the  space  comprised 
between  the  oesopbagus,  the  stomach,  and  the  matrix.  It  was  com- 
posed of  a  short  tube,  ciliated  on  the  interior  surface  (swollen  in 
the  middle),  which  on  the  one  hand  opened  into  the  matrix  not  far 
from  its  external  orifice,  and  on  the  other  opened  obliquely  into  the 
cavity  of  the  body,  by  a  mouth  slightly  bell-shaped  and  furnished 
with  active  vibratile  cilia. 

This  organ,  provided  with  a  vibratile  mouth,  and  placing  the 
cavity  of  the  body  in  communication  with  the  exterior,  has  all 
the  characters  of  a  segmental  organ.  It  appears  very  early  in 
the  bud.  When  the  stomach  is  only  outlined,  and  before  the  ten- 
tacles appear,  a  ciliary  movement  is  seen  at  the  place  which  it  sub- 
sequently occupies. 

M.  Joliet  observed  the  same  organ  in  a  second  species  of 
Pedicellina,  and  in  Loxosoma,  and  he  considers  that  in  the  Endoproct 
Polyzoa  may  be  regarded  as  constant  the  presence  of  an  organ 
widely  distributed  in  the  worms.  In  face  of  the  attempts  which  have 
been  made  in  later  years  to  bring  the  Polyzoa  and  the  Annelida 
together,  it  seems  to  him  useful  to  put  forward  his  observations. 

Power  of  Locomotion  in  the  Tunicata. — Mr.  W.  Macleay,  F.L.S., 
has  observed,*  with  some  astonishment,  that  large  Ascidians  which 
he  found  strewn  at  low  water  on  a  sandy  beach  after  a  storm,  are  or 
seem  to  be  capable  of  a  certain  amount  of  locomotion — they  do 
change  their  positions  most  undoubtedly ;  in  doing  so  they  leave 
upon  the  wet  sand  a  distinct  track  in  accordance  with  the  weight 
and  size  of  the  mass,  and  these  movements  are  not  in  any  way 
attributable  to  winds  or  waves.  He  at  first  thought  it  possible  that 
the  movements  might  be  due  to  the  agency  of  some  of  the  animals 
adhering  to  the  outside  of  the  mass,  but  he  found  that  the  only 
organic  attachments,  excepting  a  few  small  shells,  were  clusters  of 
simple  Ascidians  utterly  incapable,  therefore,  of  combined  action,  and 
much  too  small  for  their  individual  efforts  to  produce  any  effect. 

Notwithstanding,  however,  this  apparently  convincing  evidence, 
he  is  indisposed  to  believe  it  possible  that  an  animal  so  completely 
shut  up  in  a  thick  coriaceous  unmuscular  sac,  can  have  any  power  of 
external  movement,  nor  is  it  likely  that  such  a  power  would  be 
possessed  by  an  animal  whose  whole  life  (except  in  infancy)  has  to 
be  passed  firmly  rooted  to  the  bottom  of  the  sea,  and  he  hopes  that 
some  one  having  the  leisure  and  opportunity  will  endeavour  to  solve 
this  problem. 

Extension  of  the  coiled  Arms  in  Rhynchonella.— Years  ago  Von 

Buch  recorded  that  Otto  Frederic  Miiller  had  observed  the  Brachiopod 
Bhynclionella  iisittacea  protrude  its  arms  beyond  the  anterior  borders 
of  the  shell.  This  single  observation  was  not  widely  accepted,  and 
many   doubted  the  possibility  of  the    arms  being  exsertcd    in     this 

*  '  Proc.  Linn.  Soc.  N.  S.  Wiil,.-^,'  iii.  (187S)  55. 


NOTES   AKD    MEMORANDA.  303 

manner.  In  the  year  1872,  wliile  studying  living  UliynclioneUa  in 
the  St.  Lawrence,  Mr.  E.  S.  Morse  observed  *  a  specimen  protrude  its 
arms  to  a  distance  of  four  centimetres  beyond  the  anterior  borders  of 
the  shell,  a  distance  nearly  equalling  twice  the  length  of  the  shell. 
This  year  he  again  had  an  02Ji)ortunity  of  studying  it  in  Hakodate, 
Yesso,  and  again  observed  the  same  features.  Specimens  lying  on  the 
bottom  of  a  glass  dish  protruded  their  arms  a  short  distance,  and 
remained  in  this  position  for  hours.  The  movements  of  the  arms 
were  very  sluggish,  th(jugh  the  cirri  were  constantly  in  motion.  Some- 
times the  shells  closed  upon  the  arms  before  they  were  retracted. 
Lingula  has  the  power  of  partially  protruding  its  arms,  as  he  has 
repeatedly  observed  in  North  Carolina  and  Japanese  species.  Tere- 
hratulina  can  also  partially  protrude  the  cirri. 

Eye  of  the  Lamellibranchiata. — It  is  peculiarly  interesting  to 
observe  that  the  "  visual  purple  "  which  the  researches  of  Franz  Boll 
and  Kiihne  have  made  known  to  all  microscopists  is  to  be  observed  in 
the  eyes  of  some  of  the  Invertebrata  ;  Professor  Hensen  calls  atten- 
tion to  this  matter  ■]•  in  reference  to  certain  observations  made  by 
Krukenberg  on  the  eyes  of  the  Cephalopoda.  Hensen  has  observed  in 
Pecten  Jacohoeus,  that  the  layer  of  rods  is  distinguished  from  the 
surrounding  parts  by  its  coloration.  Krukenberg  in  his  notice  con- 
cludes that  in  the  Cephalopoda  the  colour  is  persistent,  but  in  Pecten 
Hensen  noted  its  ra2)id  disappearance.  Hensen  also  corrects  some 
of  his  observations  on  the  eye  of  this  Lamellibraucb,  which  were 
published  a  few  years  ago. 

Foot  of  the  TTnionidae. — J.  Carrier e  bas  been  making  some  obser- 
vations J  on  the  foot  of  the  Unionidee,  which  have  led  him  to  the 
following  conclusions  :  the  injections  of  the  lacunae  and  blood-vessels, 
which  one  is,  at  times,  able  to  make  through  a  cleft  at  the  margin  of 
the  foot,  are  effected  by  the  destruction  of  fine  tissues ;  this  cleft  does 
not,  that  is,  communicate  with  the  vascular  system,  but  is  the  aper- 
ture of  a  closoil,  and  variously  developed  gland.  This  organ  often 
contains  a  yellow  secretion.  The  various  stages  of  its  development 
are  indicated,  and  it  is  pointed  out  that  it  is  greatly  reduced  in  Unlo, 
where  indeed  it  may  be  merely  represented  by  a  short  ciliated  canal. 
It  is  concluded  that  it  represents  a  rudimentary  byssus  gland,  and 
the  author  promises  more  complete  details. 

"Digger"  Mollusc  and  its  Parasites. — The  little  digger,  Donax 
fossor,  represents  a  countless  mass  of  life  off  Cape  May,  New  Jersey, 
large  areas  looking  like  barley  grains  lying  on  a  malting  floor 
when  the  tide  retires.  It  gets  imcovered  by  the  breaking  surf  and 
instantly  reburies  itself  with  its  powerful  foot  when  the  waves  retire. 
The  siphons  are  long  and  active,  looking  like  so  many  wriggling 
worms.  Although  the  prey  of  shore  birds  and  fishes,  and  beset  with 
parasites,  they  lie  so  thick  as  even  to  interfere  with  one  another  in 
burying  themselves.      The  liver  of   these  bivalves  is  always  found 

*  'Am.  Jour.  Sci.  and  Arts,'  xvii.  (1879)  257. 

t  '  Zool.  Anzeiger,'  i.  30.  +  Ibid.  (1878)  55. 


304  NOTES    AND    MEMOKANDA, 

beset  by  flukes,  from  half-a-dozon  to  several  dozen,  and  a  bcll-sbaped 
tricbodina  crowds  tbe  brancLial  cavity.* 

Hermaphroditism  in,  and  the  Spermatophores  of  the  Nephro- 
pneustous  Gasteropoda. — Dr.  Pfeffer  describes  f  tbe  arrangement  of  tbe 
generative  organs  of  some  of  tbe  Nanidina  in  tbe  Berlin  Museum  ;  tbe 
genus  Trochanina  is  founded  on  external  characters,  but  tbe  examination 
of  tbe  internal  parts  has  brought  to  light  variations  in  structure,  which 
should  lead  to  tbe  breaking  up  of  the  genus.  The  forms  which  com- 
pose it  are  distinguished  by  having  an  accessory  gland  to  the  penis 
and  by  tbe  absence  of  tbe  retractor  muscle  of  this  organ ;  in  T. 
Schmelziana  and  T.  radians  the  seminal  duct  is  connected  with  the 
lower  portion  of  the  penis  by  well-developed  connective  tissue,  but  in 
the  other  species  it  is  connected  by  a  muscle  with  tbe  uppermost  parts 
of  tbe  uterus.  In  some  still  more  divergent  forms  there  is  a  duct  con- 
necting tbe  prostate  with  the  stalk  of  tbe  vesicle. 

The  arrangements  in  T.  ibuensis  are  such  as  to  make  copulation 
impossible,  as  the  penis  has  no  efferent  duct,  and  the  sole  orifice  is 
that  which  belongs  to  tbe  oviduct ;  the  presence,  however,  of  tbe  just- 
mentioned  duct  atones  for  this  structural  defect,  or,  in  other  words, 
renders  the  penis  unnecessary.  In  T.  percarinata  the  duct  was  like- 
wise present,  and  no  orifice  could  be  detected  in  the  penial  papilla. 
In  tbe  other  forms  there  are  no  apparent  arrangements  for  self- 
impregnation,  though  there  are  difficulties,  such  as  for  example  tbe 
absence  of  a  retractor  penis,  set  in  tbe  way  of  reproduction  by 
copulation. 

Tbe  spermatophores  were  found  in  tbe  penis,  or  in  tbe  bladder, 
and  there  might  be,  in  different  species,  one,  two,  or  even  tbree  of 
these  bodies,  with  fragments  of  others.  They  exbibit  in  most  cases 
tbe  same  general  cbaracters ;  they  form  a  sausage-sbai^ed  body  in- 
vested in  a  thin,  white,  horny  covering,  provided  at  one  end  with 
a  spine-sbaped  projection,  and  continued  at  the  other  into  a  thinner, 
long,  dark  brown  tube ;  this  tube  becomes  semicircular  towards  its 
free  end  and  terminates  in  an  enlargement,  which  is  provided  with 
one  or  two  crowns  of  spines.  When  acted  upon  by  water,  the  contents 
swell  towards  this  end  ;  they  are  then  seen  to  contain  a  number  of 
hyaline  chitinous  fibres,  and  some  oval  or  lancet-sbaj^ed  calcareous  cor- 
puscles, such  as  are  generally,  if  not  always,  found  in  tbe  penis  of  the 
Zonitidce.  Tbe  spermatophores  are,  it  is  concluded,  developed  in  tbe 
flagellum  of  tbe  penis,  or  tlirougb  tbe  whole  extent  of  this  organ  ;  and, 
from  tbe  complexity  of  their  structure,  it  is  thought  to  be  unlikely 
that  there  is  a  second  formation  of  spermatophores  during  tbe  same 
copulation  period. 

Mucous  Threads  of  Limax. — Dr.  Eimer,  having  described  |  the 
habits  of  Limax  agrestis,  and  having  observed  that  he  was  unable  to 
find  any  reference  to  their  powers  of  producing  mucous  tbreads, 
induced  Professor  Martens  to  make  some  remarks  on  tbe  subject,  §  of 
which  it  may  be  interesting  to  give  a  short  account. 

*  'Nature,' xix.  (1879)470. 

t  '  Arcli.  fiir  NaturKescliiclite,'  xliv.  (1878)  420. 

X  'Zool.  Anzoiger,'  i.  (1878)  123.  §  Ibid.  249. 


I 


NOTES    AND    MEMORANDA.  305 

Martin  Lister,  two  hundred  years  ago,  noted  the  production  of  fila- 
ments 2  feet  long;  Shaw,  in  1776,  observed  filaments  8  feet  from  the 
groimd,  and  Hoy,  in  1789,  gave  an  account  of  them  to  the  Linnaean 
Society.  For  many  years  these  and  similar  observations  seem  to  have 
been  well  known,  but  since  the  time  of  Woodward,  Johnston,  and 
Moquin-Tandon,  no  information  is  given  in  the  more  popular  manuals. 
Professor  Martens  notes  as  a  curious  fact  that  the  majority  of  obser- 
vations on  the  habits  of  Limax  has  been  made  in  Great  Britain,  anp, 
though  making  full  allowance  for  the  superior  advantages  of  our 
damp  climate,  thinks  that  the  fact  is  due  to  the  better  instruction  and 
greater  interest  of  our  naturalists.  He  observes,  that  the  power  of 
producing  these  threads  is  not  confined  to  Limax,  but  that  Megalo- 
mastoma  suspensum  in  the  West  Lidies,  and  Potamides  obtosus  on  the 
coasts  of  Borneo,  have  been  observed  to  have  it  also ;  and,  noting  the 
striking  resemblance  between  these,  and  the  byssus-threads,  concludes 
by  observing  that  there  are  marine  Gasteropoda  capable  of  producing 
similar  filaments. 

BOTANY. 

A.     GENERAL,    INCLUDING    EMBRYOLOGY    AND 
HISTOLOGY  OE  THE  PHANEROGAMIA. 

Development  of  the  Embryonal  Sac. — The  following  are  the 
summarized  results  of  M.  J.  Vesque's  researches  on  this  subject.* 

1st.  In  Angiosperms,  the  embryonal  sac  of  Brougniart  is  not 
composed,  as  in  Gymnosperms,  of  a  single  cell;  on  the  contrary, 
it  results  from  the  fusion  of  at  least  two  cells  superposed  and  at  first 
separated  by  septa. 

2nd.  The  cells  which  are  destined  later  on  to  compose  the  em- 
bryonal sac,  all  proceed  from  one  and  the  same  primordial  parent- 
cell.  M.  Warming,  who  discovered  them,  rightly  gives  them  the 
name  of  special  parent-cells,  comparing  them  to  the  parent-cells  of 
pollen  or  of  spores.  This  comparison  is  justified  by  the  physical 
characters  of  the  septa. 

3rd.  When  the  development  of  the  special  parent-cells  is  com- 
pleted, each  gives  rise  to  four  vesicles  homologous  to  the  four  pollen 
grains  which  originate  in  one  and  the  same  parent-cell. 

4th.  The  variations  to  be  observed  in  the  different  types  of 
Angiosperms  depend  on  the  more  or  less  early  arrest  of  development 
which  happens  to  the  special  parent-cells. 

5th.  The  first  cell  always  produces  the  sexual  apparatus.  It 
blends  with  the  second  cell,  in  order  to  constitute  the  major  part  of 
the  embryonal  sac.  When  the  second  cell  has  produced  its  four 
vesicles,  the  eight  free  vesicles  of  the  embryonal  sac  behave  in  the 
manner  described  by  Strasburger  in  the  cases  of  Orchis  and 
Monotropa.  This  fact  is  observed  in  certain  Monocotyledons  and 
apopetalous  Dicotyledons. 

6th.  The  other  special  parent-cells  (the  third,  fourth,  and  fifth) 

may  produce  the  four  vesicles.     Each  of  the  vesicles  is  homologous 

with  the  pollen  grain,  and  it  is  convenient  to  retain  for  it  the  name 

of  antipodal  vesicle.     When  these  parent-cells  persist  in  their  primi- 

*  '  Ann.  des  Sci.  Nat.  (Bot).,"  xi.  (1878)  27G. 

VOL.    II.  X 


o06  NOTES   AND    MEMORANDA. 

tive  state  without  producing  vesicles,  they  themselves  simulate  super- 
posed, not  juxtaposed,  antipodal  vesicles.  These  differ  from  the 
former  in  a  morphological  point  of  view,  and  M.  Vesque  gives  them 
the  name  of  anticlinal  cells. 

This  state  Las  been  observed  in  several  Monocotyledons,  certain 
apoi^etalous  Dicotyledons,  and  in  almost  all  the  Gamopetalfe. 

7th.  The  second  cell  appears  to  be  the  first  to  undergo  an  arrest 
of  development.  In  this  case  its  vesicle  directly  becomes  the  proper 
vesicle  of  the  embryonal  sac,  and  this  cell  does  not  produce  any 
antipodal  vesicle.  This  fact,  observed  in  some  Monocotyledtms  and 
Apopetalfe,  becomes  the  rule  in  the  Gamopetalte,  which  are  from  this 
point  of  view  the  farthest  removed  from  Cryptogams. 

8th.  In  the  Gamopetalte  (with  some  very  rare  exceptions)  the  first 
cell  alone  produces  a  complete  or  incomplete  tetrad,  which  is  nothing 
but  the  sexual  apparatus  composed  of  two,  three,  or  four  vesicles. 
The  second  cell  seems  to  take  upon  itself  the  vegetative  role  of  the 
embryonal  sac.  Its  undivided  vesicle  becomes  the  vesicle  of  the 
embryonal  sac. 

The  cells  3,  4,  5  (or  3,  or  3  and  4,  according  to  the  number  of  the 
special  parent-cells)  are  anticlinal  vesicles,  or  produce  antipodal 
vesicles  by  dividing  their  vesicles. 

9th.  In  the  greater  number  of  Gamopctalae,  the  formation  of  the 
endosjjerm  is  connected  with  the  ulterior  develojiment,  by  division, 
of  one  or  many  of  the  special  parent-cells.  These  Litter  being  homo- 
logous with  the  parent-cells  of  spores,  it  is  permissible  to  consider 
the  endosperm  of  these  plants  as  a  sterile  female  prothallus. 

Protein-crystalloids. — Dr.  A.  F.  W.  Schimper,  son  of  the  well- 
known  bryologist,  has  recently  published  a  treatise  on  this  subject.* 
He  finds  the  crystalloids  contained  in  seeds,  to  which  he  has  paid 
most  attention,  to  belong  mostly  to  two  systems ;  some  are  hexa- 
gonal-rhombohedral-hemihedial ;  while  others  ai-e  regular  tetrahedral- 
hemihedral ;  the  former  again  being  divisible  into  three  species. 
Their  crystallographic  properties  agree  with  those  of  true  crjfstals, 
except  that,  as  Niigeli  has  already  pointed  out,  their  angles  are  some- 
what less  constant.  Regular  crystalloids  swell  up  in  water  equally 
in  all  directions,  and  therefore  undergo  no  change  in  form ;  the 
swelling  of  hexagonal  crystalloids  is,  on  the  other  hand,  accompanied 
by  certain  changes  both  of  form  and  of  optical  properties.  Crystal- 
loids are,  however,  perfectly  distinct  from  true  crystals ;  the  same 
substance  never  occurs  both  as  crystalloid  and  crystal. 

Composition  of  Chlorophyll.— Some  further  researches  on  this 
subject  are  recorded  by  Professor  Dippel.f  He  starts  with  the  obser- 
vation that  neither  of  the  substances  into  which  Kraus  divided  crude 
chlorophyll,  xanthophyll  and  cyaiiophyll,  are  themselves  simple  sub- 
stances. Xanthophyll,  which  is  not  entirely  free  from  fluorescence, 
and  which  is  certainly  not  a  product  of  decomposition  due  to  the 
presence  of  water  in  the  alcohol  employed,  is,  according  to  circum- 
stances, coloured  of  a  more  or  less  distinct  blue  by  acids,  and  this 

*  '  Botamsclie  Zeitiing,'  xxxvii.  (1879)  45.  f  'Flora,'  xxxvi.  (1878)  17. 


NOTES    AND    MEMORANDA.  307 

blue  fluid  can  be  decomposefl,  by  agitation  with  benzin,  into  a  yellow 
and  a  blue  constituent  Cyanophyll  can  also,  like  crude  chlorophyll, 
be  decomposed,  both  by  agitation  and  by  treatment  with  potash  and 
alcohol,  into  a  yellow  and  a  green  constituent.  From  an  alcoholic 
solution  of  crude  chlorophyll  or  from  cyanophyll  there  can,  however, 
be  obtained,  by  treatment  with  potash  and  ordinary  benzin,  a  pure 
yellow  substance  called  by  Kraus  xanthin,  in  which  there  is  no  trace  of 
fluorescence,  which  is  not  coloured  blue  by  acids,  and  which  is  also  recog- 
nized by  presenting  three  clearly  defined  absorption-bands  in  the  more 
highly  refrangible,  and  a  weak  band  (?)  in  the  less  refrangible  part  of 
the  spectrum.  If  the  potash  is  precipitated  from  the  alkaline-alcoholic 
solution  which  is  obtained  in  the  production  of  xanthin,  by  means  of 
very  dilute  sulphuric  acid,  a  beautiful  green  or  bluish-green  alcoholic 
solution  is  obtained,  in  which  tlie  green  constituent  of  chlorophyll  is 
contained,  termed  by  Kraus  cldorin.  This  solution,  which  resembles 
chlorophyll  in  its  colour,  its  fluorescence,  and  in  its  property  of  being 
turned  blue  by  acids,  must  be  considered  rather  as  a  mixture  than  as 
a  product  of  decomposition.  The  yellow  colouring  matter  of  leaves 
and  of  golden  yellow  petals,  which  is  soluble  in  alcohol,  presents 
precisely  the  same  spectroscopic  phenomena  as  the  yellow  ingredient 
of  chlorophyll  obtained  by  shaking  with  benzin.  From  the  absorp- 
tion phenomena  of  the  crude  alcoholic  extract  of  the  petals  of  Esch- 
scholtzia  californica,  it  is  evident  that  we  have  a  mixture  of  two 
constituents,  one  reddish  yellow  and  soluble  in  water  and  alcohol,  the 
other  golden  yellow,  and  soluble  in  alcohol,  but  not  in  water.  The 
residts  are  the  same  with  the  yellow  colouring  matter  of  the  petals  of 
HemerocaUis  fulva  and  Dumortieri,  and  the  ligulate  petals  of  the  mari- 
gold ;  and  it  seems  not  improbable  that  the  absorption  phenomena  of 
other  more  or  less  strongly  coloured  orange  petals  and  coatings  to 
the  fruit,  such  as  those  of  Berberis  Darwinii  and  Euonymus  europcBus, 
are  due  to  similar  causes. 

B,  CRYPTOGAMIA. 

Action  of  Light  and  Heat  on  Swarmspores  (Zoospores).— In 
opposition  to  the  observation  of  many  botanists  that  swarmspores  in 
water  group  themselves  in  a  determinate  way  under  the  influence  of 
light,  Sachs  has  shown  by  experiment  that  in  emulsions  consisting  of 
oil  and  a  mixture  of  alcohol  and  water,  the  fine  oil  drops  also  show 
similar  groupings,  and  that  these  are  caused  by  currents  in  the  fluid 
produced  by  difl:erences  of  temperature. 

All  that  had  been  published  on  the  subject  was  reconcilable  with 

these  results,  but  a  statement  of  Dodel-Port  on  the  behaviour  of  the 

swarmspores  of  UlofJirix  clashed  with  this  explanation.     According  to 

him,  the  spores  in  the  vessels  collected  on  the  side  next  the  window, 

which,  as  the  experiment  was  made  in  winter,  was  the  colder  side, 

while  on  the  other  side  they  flowed  towards  a  lighted  petroleum  lamp, 

and  consequently  to  the  warmest  side.     Strasburger  then  took  up  tlie 

subject,  and  submitted  it  to  a  thorough  experimental  examination,  the 

results   of  which  are    published    in   the  '  Jenaische   Zeitschrift   fiir 

Naturwissenschaften.'  *  ^  ,    ,     ..   ,. 

*   \  ol.  xn.  5a I. 

2  X 


308  NOTES    AND    MEMORANDA. 

Strasburger  first  repeated  most  of  the  experiments  of  Sachs,  both 
with  emulsions  and  with  swarmspores,  and  found  the  same  results  in 
every  case.  But  besides  these  passive  groupings  of  the  swarmspores 
caused  by  currents,  he  observed  some  that  were  caused  by  active 
movements  on  their  part.  These  were  examined,  not  in  large  vessels, 
but  in  drops  which,  hanging  from  the  covering  glass  in  a  moist 
chamber,*  could  be  examined  under  the  Microscope. 

The  experiments  were  carried  further  by  applying  light  of  different 
colours,  either  by  passing  it  through  different  coloured  solutions 
before  it  reached  the  di*ops,  or  by  directing  the  different  parts  of  an 
objective  sj^ectrum  on  the  drops.  Lastly,  in  experimenting  on  the 
action  of  heat,  the  incident  rays  were  sometimes  made  to  lose  their 
calorific  rays  by  a  concentrated  solution  of  alum,  sometimes  their 
luminous  rays  by  a  solution  of  iodine  in  bi-sulphuret  of  carbon. 

The  very  first  experiment  showed  that  in  such  drops  certain  swarm- 
spores often  moved  in  a  direct  course  either  to  or  from  the  source  of 
light ;  that  the  movement  often  took  place  with  considerable  rapidity  ; 
that  it  commenced  the  moment  the  j)reparation  was  exposed  to  the 
influence  of  the  light ;  that  a  change  in  the  position  of  the  prepara- 
tion relatively  to  the  source  of  light  resulted  in  an  immediate  corre- 
sponding change  in  the  direction  of  the  movement  of  the  spores.  It 
had  then  to  be  determined  whether  any  and  what  share  in  these  move- 
ments was  so  due  to  currents  within  the  drop,  and  with  this  object  the 
same  experiments  were  repeated  with  emulsion  drops.  The  currents, 
which  could  then  be  easily  detected  in  the  drop,  were,  however,  under 
the  same  conditions  and  in  the  same  localities,  not  to  one  side  only  as 
in  the  case  of  swarmspores,  but  always  in  a  very  different  direction, 
namely,  towards  a  common  centre. 

Stronger  evidence  that  active  movements  were  the  cause  of  the 
grouping  of  the  swarmspores  in  the  drops  was  furnished  by  experiments 
in  which  different  spores  in  the  same  drop  were  exposed  to  light  from 
one  side ;  when  some  went  towards  the  light,  whilst  the  others 
removed  from  it  or  remained  perfectly  still.  Of  the  same  nature  were 
the  results  of  experiments  made  with  finely  divided  inorganic  sub- 
stances (amorphous  bromine)  and  with  swarmspores  which  had  been 
killed  by  heat  or  by  slight  admixture  with  a  noxious  substance ;  they 
showed  none  of  the  movements  which  were  displayed  by  the  living 
spores  in  drops  of  water. 

Having  thus  settled  the  general  phenomenon,  Strasburger  pro- 
ceeded to  the  special  examination  of  the  behaviour  of  different  swarm- 
spores under  light.  For  this  purpose  he  used  chiefly  those  ot  Hcemafo- 
coccus  lacusfris,  Ulothrix  zonaia,  Chcetomorplia  acrea,  Ulva  enteromorpha, 
lanceolata  and  ^  compressa,  Ulva  Lactuca,  Botrydium  granulatum, 
Bryopsis  pliimosa,  CEdogonium  and  Vmicheria,  Scyfosiphon  lomeniarium, 
Chytridium,  and  Saprolegnia,  the  swarmspore  conditions  of  Chilomonas 
curvata  and  Paramecium,  and  others.  The  behaviour  of  these 
numerous  swarmspores  with  respect  to  light  was  examined  under 
widely  differing  conditions.  He  also  examined  their  behaviour  in  the 
dark,  the  effect  of  heat  and  other  external  influences,  that  of  currents 
*  See  this  Journal,  i.  (1878)  197. 


NOTES   AND    MEMORANDA.  309 

in  distributing  the  spores  in  large  vessels,  and  tlie  effect  of  light  on 
the  movements  of  other  plant-organs. 

The  following  are  the  general  results  arrived  at : — 

The  direction  of  the  movement  of  certain  swarnispores  is  influenced 
by  the  light :  these  may  be  termed  phototactic.  This  action  is  con- 
nected only  with  the  protoplasm  as  such,  and  not  with  any  definite 
colouring  matter,  for  colourless  spores  act  like  coloured  ones. 

The  swarmspores  affected  by  light  move  in  the  direction  of  the 
incidence  of  the  light,  and  this  takes  place  in  two  ways :  either  it  is 
constant  only  in  the  direction  of  the  source  of  light  even  when  the 
intensity  of  the  light  decreases  in  this  direction,  when  the  swarmspores 
may  be  called  aphotometric  ;  or  they  follow  the  decrease  of  light  in 
the  direction  of  rising  or  falling  intensity,  when  they  may  be  called 
photometric.  No  movement  is  possible  in  any  other  direction  than 
that  of  the  incidence  of  the  light,  even  when  the  intensity  of  the 
illumination  rises  or  falls  in  any  other  direction. 

The  blue,  indigo,  and  violet  rays  alone  have  any  influence  on  the 
phototactic  spores,  and  the  maximum  effect  is  produced  by  the  indigo. 
On  the  other  hand,  the  yellow  and  nearly  allied  rays  of  sufficient 
intensity  cause  a  quivering  movement  in  phototactic  spores. 

On  a  sudden  change  in  the  brightness,  many  phototactic  swarm- 
spores show  after  effects,  the  direction  of  the  movement  induced  by  the 
previous  degree  of  brightness  being  retained  for  a  short  time. 

The  large  swarmspores  of  Bryopsis  show  after  effects  only  when  the 
intensity  of  the  light  is  suddenly  diminished  ;  when  it  is  suddenly 
increased,  they  exliibit  a  trembling  which  makes  them  leave  their 
course  for  a  while.  Those  of  JBotrydium  do  not  show  after  effects 
when  the  brightness  is  either  suddenly  increased  or  decreased,  but 
they  tremble  if  the  light  is  suddenly  cut  off.  The  swarmspores  of 
TJlvcB  gave  no  sign  either  of  after  effect  or  trembling. 

An  increase  in  the  intensity  of  the  light  occasions  in  the  photo- 
tactic spores  for  the  most  part  a  tendency  to  settle ;  direct  sunlight 
more  particularly  acts  in  this  way  ;  decrease  in  the  intensity  of  the 
light  heightens  their  mobility. 

The  rapidity  of  the  movement  is  not  influenced  by  light ;  the 
spores,  however,  move  in  a  more  direct  course  the  greater  the  intensity 
of  the  light. 

In  general,  moreover,  the  smaller  spores  move  straighter  than  the 
larger  ones.  The  largest,  by  vii'tue  of  their  important  property  of 
moving  in  considerable  masses,  have  freed  themselves  from  the 
influence  of  light  on  their  direction.  But  there  are  also  small  spores 
which  are  influenced  comparatively  slightly,  or  not  at  all,  by  light. 

In  the  dark  the  phototactic  swarmspores  do  not  settle  to  rest 
unless  they  are  sexually  differentiated  and  unite  with  one  another. 
Otherwise  they  continue  to  move  till  they  disappear. 

In  swarmspores  brought  from  the  dark  into  the  light,  similar 
effects  may  be  observed  as  when  subjected  to  a  sudden  increase  in  the 
brightness. 

In  general,  photometric  swarmspores  alter  in  their  sensitiveness  to 
light  in  the  course  of  their  development,  this  being  displayed  more 


310  NOTES   AND    MEMORANDA. 

wlien  they  are  young  than  when  they  are  old  ;  and  it  exhibits  also 
other  variations. 

Apart  from  the  alteration  in  sensitiveness  during  development, 
whole  batches  show  themselves  to  be  directly  sensible  to  relatively 
higher  or  lesser  intensities  of  light.  This  appears  to  depend  on  the 
intensity  of  the  light  in  the  spot  where  they  were  produced. 

Heat  exercises  for  the  most  part  an  influence  on  the  photometric 
sensitiveness  of  swarmspores.  As  the  temperature  rises  they  become 
in  general  more  sensitive  to  light,  less  so  as  it  sinks. 

If  there  is  not  a  free  current  of  air  through  the  batches,  photo- 
metric swarmspores  are  sensitive  to  higher  intensities  of  light. 

Insufficient  nutriment  prevents  the  swarmspores  from  coming  to 
rest,  without  influencing  their  sensitiveness  for  light.* 

Floating  Algae  forming  Scum  on  the  Surface  of  Water.— The 
cause  of  the  sudden  appearance  of  green,  red,  or  brown  scum  on  the 
surface  of  water,  when  due  to  an  algoid  growth,  must  be  either  an 
extraordinarily  rapid  multiplication  of  the  alga,  or  a  change  in  its  spe- 
cific gravity,  in  consequence  of  which  it  rises  from  the  bottom  to  the 
surface  of  water,  such  as  occurs  also  in  the  terminal  buds  of  flowering 
water-plants,  as  HydrocJiaris,  Sfratiotes,  CeratophyUum,  Myriophyllum, 
Aldrovanda,  Utricularia,  &c.  The  organism  which  constitutes  this 
"  Wasser-bliithe  "  is  usually  some  green  alga  belonging  to  the  Chroo- 
coccacefe,  Oscillatorieae,  or  Nostocaceas.  Professor  F.  Cohn  has  for 
the  first  time  detected  a  Mivularia  "j"  as  the  cause  of  this  appearance,  on 
a  stream  near  Lauenburg,  in  Pomerania,  the  surface  of  which  was 
completely  covered  with  a  green  scum,  consisting  of  an  innumerable 
quantity  of  minute  globes  from  0 '  15  to  0-3  mm.  in  diameter,  bearing 
a  superficial  resemblance  to  Volvox.  Under  the  Microscope  they  were 
found  to  consist  of  Kivularia-filaments  imbedded  in  jelly,  formed  of 
ordinary  cells  and  heterocysts.  Cohn  considers  it  a  new  species,  to 
which  he  gives  the  name  Rivularia  fiuitans. 

About  the  same  time,  C.  Gobi,  of  St.  Petersburg  |  observed  a  similar 
appearance  on  the  surface  of  the  sea-water  in  the  Gulf  of  Finland,  con- 
sisting also  of  minute  green  globes  from  0*3  to  0  •  45  mm.  in  dia- 
meter or  larger,  enclosed  in  a  very  thin  jelly,  to  which  he  gave  the 
name  Rivularia  pelagica.  The  two  sj^ecies  were  subsequently  deter- 
mined by  Professor  Cohn  to  be  indistinguishable  from  one  another. 
The  marine  form  was  seen  only  when  the  water  was  tolerably  still, 
disappearing  completely  when  it  became  rough,  and  was  accompanied 
by  large  patches  of  another  green  alga,  Aphanizomenon  fios-aquce  Elfs., 
which  had  hitherto  been  observed  only  in  fresh  or  brackish  water. 

Luminous  Bacteria  in  Meat. — An  account  has  been  published  § 
of  some  observations  of  M.  Nuesch  on  "  Luminous  Bacteria  on  Fresh 
Meat."  A  fact  of  the  same  kind  was  noted  by  the  famous  Fabricius 
ab  Aquapendente  in  1592,  who  appears  to  have  been  the  first  to 
observe  it.     M.  Nuesch  had  some  pork  chops  which  were  sufficiently 

*  '  Der  Naturforseher,'  xi.  (1878)  485. 

t  '  Hedwigia,'  xvil.  (1878)  1. 

X  Ibid.,  33. 

i^  '  Bidl.  Sc.  Dc'p.  dii  Nord  '  (1878)  184. 


NOTES    AND    MEMORANDA. 


311 


luminous  to  enable  him  to  read  his  watch  by  their  light !  On  exami- 
nation, his  butcher  owned  that  he  first  observed  it  in  the  recess  in 
which  he  stored  the  '■  debris  destines  aux  saucisses."  Shortly  afterwards 
all  his  meat  became  phosphorescent,  and  even  fresh  meat  brought 
from  a  distance  to  his  shop  was  similarly  affected.  The  moment  the 
meat  began  to  give  indications  of  losing  its  freshness,  the  phospho- 
rescence disappeared,  and  Bacterium  termo  became  visible  on  exami- 
nation ;  cooked  meat  did  not  put  on  this  appearance,  but  cooked 
albumen  and  potatoes  did  become  phosphorescent,  and  starch  paste 
became  of  an  orange  colour  in  the  presence  of  this  phosi)horescent 
meat;  the  hands,  if  rubbed  over  it,  remained  phosphorescent  for 
several  hours.  It  is  reported  that  under  the  Microscope  bacteria 
were  observed,  and  that,  in  tlie  dark,  examination  under  the  Microscope 
revealed  a  number  of  luminous  points.  In  this  strange  history  there 
are  two  satisfactory  points ;  the  one  is  that  the  meat  did  not  diS'er  in 
smell  from  ordinary  meat,  and  the  other  is  that  we  are  promised 
fuller  details. 

Thuret  and  Bornet's  '  Phycological  Studies.'— This  magnificent 
work  surpasses  anything  which  has  ever  been  published  relating  to 
Algfe.  It  comprises  fifty-one  folio  engravings  by  Picart  from  drawings 
of  Bornet  and  Eiocreux.  Most  of  the  plates  were  prepared  under 
Thuret's  direction  between  the  years  1846  and  1856,  and  several 
appeared  in  a  reduced  form  in  the  '  Annales  des  Sciences  Naturelles ' 
of  1851,  as  illustrations  of  his  article,  '  Eecherches  sur  les  Zoospores 
des  Algues.'  It  was  Thuret's  intention  to  publish  an  atlas  of  fifty 
plates,  but,  at  the  time  of  his  premature  death,  ten  of  the  plates  had 
not  been  engraved.  These  were  finished  under  the  direction  of  his 
friend  and  co-worker.  Dr.  Bornet.  Never  before  have  the  Algse  been 
so  exquisitely  delineated,  whether  microscopically  or  in  gross.  The 
life-size  figure  of  Fiicus  plati/cat^nis  is  perfection  itself.  The  text  is 
principally  by  Dr.  Bornet,  who  has  inserted  when  possible  the  notes 
and  descriptions  of  Thuret  himself.  No  apology,  however,  was  neces- 
sary on  the  part  of  the  former ;  for  not  only  was  he  the  constant 
companion  of  Thuret,  but  his  style  of  writing  very  closely  resembles 
that  of  his  lamented  associate.  The  text  modestly  purports  to  be 
simply  a  description  of  the  plates.  It  is,  however,  much  niore ;  it  is 
a  very  elaborate  exposition  of  the  structure  and  reproduction  of  the 
different  groups  of  Algas.  The  principal  part  of  the  observations  on 
the  Fucaceae  have  already  appeared  in  the  '  Annales.'  _  The  part 
relating  to  the  Phaeosporefe  is  very  clearly  presented,  and  is  the  most 
complete  account  of  the  order  yet  published.  The  fertilization  of 
Polyides  rotundus  resembles  that  of  Dudresnaya  in  the  growth  of  a 
number  of  filaments  from  the  base  of  the  trichogyne.  The  account 
of  the  reproduction  in  the  Corallinese  throws  a  new  light  on  the 
structure  of  that  order,  and  for  the  first  time  a  detailed  account  is 
given  of  the  antheridia  and  cystocorpic  spores.* 

Relation    of   Lichens    to   Algae    and  Fungi.  —  The  theory  of 
Schwendeuer,  that  lichens  are  not  independent  organisms,  but  consist 

*  'Am.  Jouni.  Sci.  and  Artt-,'  xvii.  (1879)  256. 


312  NOTES   AND   MEMORANDA. 

of  fungi  parasitic  upou  Algte,  although  not  generally  accepted  by 
lichenologists,  has  met  with  great  favour  from  physiologists.  Dr.  A. 
Minks  promises  an  important  work  in  opposition  to  this  theory, 
founded  on  a  long  series  of  experiments,  and  to  be  illustrated  by  a 
large  number  of  coloured  plates.  In  the  meantime  he  gives  a  state- 
ment of  his  conclusions,  with  some  of  the  arguments  on  which  they 
are  founded,  in  '  Flora.'  *  His  observations  were  made  mainly  on  a 
gelatinous  lichen,  Leptogium  myochroum,  Ehrh.,  and  with  a  Hart- 
uack's  objective  with  a  power  of  1250.  All  the  preparations  were 
made  in  filtered  river-water,  to  which  was  usually  added  a  larger  or 
smaller  quantity  of  potash  ("  liquor  kali  caustici "  of  the  German  phar- 
macopceia,  Sd^  per  cent.).  In  order  to  remove  the  jelly,  the  prepara- 
tion was  further  heated  with  potash  for  ten  minutes,  every  trace  of 
the  alkali  washed  away,  and  dilute  sulphuric  acid  gradually  added 
to  the  water  in  which  the  preparation  lay.  While  the  destructive  in- 
fluence of  the  acid  on  the  true  constituents  of  the  lichen  is  very  slow, 
it  has  a  remarkable  effect  on  the  contents  of  the  cells,  changing  the 
blue-green  of  the  gonidia  at  once  into  a  more  or  less  intense  steel-blue. 
A  close  observation  of  the  thallus  of  the  lichen  in  question  shows, 
says  Dr.  Minks,  that  there  is  no  clear  distinction  between  the  cells 
of  the  hyphae  and  the  gonidia,  one  passing  over  insensibly  into  the 
other,  the  two  being  contrasted  simply  as  different  modifications  of 
the  same  cell.  The  cloudy  granular  contents  of  the  gonidia  appear, 
when  very  highly  magnified,  as  a  colourless  protoplasm  permeated 
by  a  smaller  or  larger  quantity  of  intensely  blue-green  corpuscles. 
The  colourless  contents  of  the  hyphal  cells  also  consist  of  a  pro- 
toplasm, but  in  their  axis  is  a  single  row  of  similar  but  more  delicate 
blue-green  corpuscles.  The  presence  of  these  corpuscles,  termed  by 
Korben  microgonidia,  serve  to  distinguish  the  cells  of  lichens  from  those 
of  fungi,  and  are  the  origin  of  all  intracellular  new-formation  of  cells. 
The  microgonidia  may  be  considered  as  the  germ  of  the  new-forma- 
tion of  gonidial  chains.  A  row  of  microgonidia,  increasing  by  the 
division  of  its  separate  corpuscles,  increases  the  size  of  the  cell  which 
encloses  it  to  its  utmost  capacity ;  this  mother-cell  ultimately  becomes 
dissolved  into  jelly,  and  the  young  chain  of  gonidial  cells  is  thus  set 
free.  The  microgonidia  gradually  grow  and  finally  become  invested 
each  in  its  own  cell-wall,  beboming  thus  transformed  into  ordinary 
gonidia.  In  this  way  an  ordinary  hypha  of  the  thallus  may  become 
transformed  into  a  chain  of  gonidia.  The  gonidial  cells  soon  lose  all 
indication  of  their  origin,  and  increase  by  the  ordinary  repeated 
bipartition  or  quadripartition.  Some  cells,  however,  take  no  part  in 
this  multiplication,  remaining  unchanged  in  the  form  of  what  are 
known  as  heterocysts  or  metrogonidia,  which  also  contain  microgonidia, 
like  the  ordinary  cells.  The  two  differentiated  products  from  the 
same  original  fundamental  tissue  —  ordinarily  called  the  gonidial 
system  and  the  hyphal  system — our  author  proposes  to  term  gonidema 
and  gono-hyphema,  the  latter  always  having  a  potentiality  to  pass 
over,  at  some  time  or  other,  into  the  former.  In  addition  to  these, 
the  lichen-thallus  contains  a  third  tissue,  hitherto  neglected,  the 
*  'Flora,"  xxxvi.  (1872)  209  ct  seq. 


NOTES    AND   MEMORANDA.  313 

hyphema,  the  original  fundamental  tissue  out  of  which  the  gono- 
hyphas  are  themselves  differentiated.  This  can  be  best  detected  in 
the  hypothalline  tissue,  at  the  point  of  origin  of  the  rhizines.  Its 
cells  are  very  minute,  and  have  not  the  elongated  form  of  those  of 
the  gono-hyphse,  but  contain,  like  them,  microgonidia.  It  will  be 
observed  that  the  structure  and  development  of  Nostoc  agree,  in  every 
essential  respect,  with  that  just  described  of  ordinary  lichens. 

In  addition  to  the  ordinary  mode  of  reproduction  of  the  thallus  of 
lichens  which  the  author  terms  hlastesis,  there  is  another  which  is  less 
known,  and  to  which  he  specially  calls  attention.  The  bodies  which 
he  calls  hormospores,  now  described  for  the  first  time,  are  similar  in 
their  mode  of  origin  to  the  stylospores  or  teleutospores  of  fungi.  They 
are  colourless,  and  contain  a  number  of  moderately  large  microgo- 
nidia, and  are  produced  on  the  rhizines  and  other  parts  of  the  lichen, 
as  the  terminal  cells  of  special  hyphae.  When  about  to  propagate, 
the  hormospore  divides  into  a  number  of  cells,  the  microgonidia  at 
the  same  time  also  increasing  rapidly.  The  mother-cell  then  de- 
liquesces into  a  jelly,  the  microgonidia  at  the  same  time  developing 
into  metrogonidia. 

The  peculiarity  of  lichens,  which  distinguishes  them  from  every 
other  class  of  vegetable  productions,  is  that  all  the  three  kinds  of 
tissue  above  described  are  capable  of  independent  reproduction ;  but 
that  no  one  of  the  three  can  itself  reproduce  a  lichen.  A  combination 
of  all  three  is  necessary  for  this  purpose ;  and  this  is  the  cause  of  the 
remarkable  appearance  which  has  given  rise  to  the  theory  that  a 
lichen  is  a  compound  structure  of  one  organism  parasitic  upon 
another. 

In  a  subsequent  paper  *  the  well-known  lichenologist.  Dr.  J. 
Miiller,  of  Geneva,  confirms  Dr.  Minks's  statement  as  to  the  develop- 
ment of  the  gonidia  of  lichens  out  of  microgonidia.  He  states  that 
he  has  been  able  to  make  out  the  microgonidia  with  ease,  with  a 
Swift's  ^-inch  objective  (a  power  of  360),  after  subjecting  the  lichen 
to  the  chemical  treatment  recommended  by  Dr.  Minks;  and  with 
Hartnack's  immersions  No.  10  and  No.  15  without  any  chemical 
preparation,  in  both  fresh  and  dried  lichens.  Dr.  Miiller  detected 
microgonidia  in  all  the  cells,  both  vegetative  and  reproductive,  of  the 
entire  lichen ;  in  the  rhizines,  cortical  cells,  medullary  hyphfe,  para- 
physes,  young  asci,  spores,  basidia,  and  spermatia,  but  most  distinctly 
in  the  medullary  hyphfe,  where  they  form  a  light  greenish  bead-like 
chain  or  row  of  minute  balls  in  the  axis  of  the  hyphae,  with  a  diameter 
of  about  o^oVo'  t^  s'ffVff  ^™'  They  are  still  more  easily  seen  in  the 
hyphae  of  heteromerous  lichens,  as  Physcia  and  Parmelia  ;  and  they 
can  also  be  made  out  without  difficulty  in  vertical  sections  through 
the  thallus  of  crustaceous  and  foliaceous  lichens.  Intermediate  con- 
ditions in  all  stages  may  be  observed  between  microgonidia  and  goni- 
dia, which  gradually  become  free  by  absorption  of  the  hyphae,  and 
then  divide.  Dr.  Miiller  concludes,  therefore,  that  the  gonidia"  of 
lichens  are  not  foreign  bodies  imbedded  in  their  tissue,  but  that  they 
originate  in  the  hyphae,  as  the  spores  in  the  asci. 

*  'Flora,'  xxxvi.  (1878)  479. 


314  NOTES    AND    MEMORANDA. 

After  many  unsatisfactory  attempts  with  dry  objectives,  and 
inferior  powers,  but  with  some  attention  to  chemical  preparation  of 
the  material,  Mr.  E.  Tuckerman,  of  the  United  States,  says  *  that  he 
has  at  last  had  the  pleasure,  with  an  immersion  ^  of  Tolles,  to  clearly 
discern  the  pale  greenish,  broken  column,  passing  into  rounded, 
microgonidium-like  masses,  contained  in,  and  seen  at  length  to  escape 
from,  the  medullary  hyphfe  of  the  Parmelia  of  Wright  Lich.  tub. 
n.  74  (there  called  by  him  P.  tiliacea,  v.  flavicans,  and  supposed  the 
same  with  the  P.  relicma,  at  least  of  IVIontagne),  reaching  this  result 
with  a  power  of  only  some  six  hundred  diameters,  and  without  other 
preparation  than  a  thorough  maceration  of  the  tissue  in  water.  With 
a  ^^  of  Tolles,  a  1-inch  eye-piece,  and  power  of  about  1000,  the  whole 
structure  and  especially  the  colour,  was  better  exhibited ;  as  it  was 
best  of  all  in  Tolles's  admirable  y^^  and  2^- 

Influence  of  Light  on  Fungi. — The  common  idea  that  not  only 
can  fungi  live  without  the  influence  of  light,  but  that  it  is  actually 
injurious  to  them,  is  contested  by  S.  Schulzer,  of  Muggenburg,|  who 
points  out,  in  support  of  his  view,  the  following  facts.  The  common 
Sphoeria  compressa  grows  upon  wood,  originating  at  various  depths 
below  the  surface.  When  it  first  makes  its  appearance,  at  a  distance 
from  the  light,  the  perithecium  is  inconspicuous,  thin,  and  colourless, 
becoming  thick  and  dark-coloured  only  on  exposure  to  light;  and  the 
same  is  true  of  several  other  Sph^eriaceae.  Cortinarius  fulgens  and 
C.  cyanus  change  their  colour,  as  they  mature,  the  one  from  light 
yellow,  the  other  from  violet,  to  brown,  and  this  can  be  shown  to  be 
due  to  the  influence  of  light,  and  not  merely  to  age.  Many  fungi  which 
are  light-coloured  and  weak  when  buried  in  grass  or  underwood,  are 
much  more  vigorous  and  of  a  darker  colour  when  exposed  to  a  stronger 
light.  Peziza  Fucheliana  always  grows  in  an  oblique  direction 
towards  the  light,  the  stem  becoming  curved  in  a  seri>entine  manner 
if  its  position  in  reference  to  the  source  of  light  is  altered  from 
time  to  time.  It  exhibits,  in  fact,  a  distinct  positive  heliotropism. 
Finally,  a  considerable  number  of  the  perennial  hard  Hymenomycetes 
belonging  to  the  Polyporei,  are  able  completely  to  develop  their 
fructification  only  when  freely  exposed  to  light. 

Spores  on  the  upper  side  of  the  Pileus  in  Hymenomycetes.— 

The  occurrence  of  a  thick  layer  of  spores  on  the  upper  side  of  the 
pileus — under  circumstances  where  they  cannot  have  fallen  down 
from  some  other  individual — has  been  observed  in  a  single  exotic 
genus  of  Agaricini,  Stylobates  Fr.,  and  in  several  species  of  Polyporei, 
especially  belonging  to  the  genera  Polyporus  and  Boletus.  No  expla- 
nation has  been  afforded  of  this  singular  circumstance  before  the 
recent  observations  of  S.  Schulzer.  J  In  a  species  newly  dis- 
covered by  him,  Polyporus  adspersus,  and  subsequently  in  several 
other  species,  he  observed  that  while  some  of  the  horizontal  hyphaB 
of  *the  pileus  bend  downwards  towards  the  hymenial  layer  consisting 

*  '  Am.  Jour.  Sci.  and  Arts,'  xvii.  (1859)  254. 
+  '  Flora,' xxxvi.  (1878)  119. 
X  Ibid.,  11. 


NOTES    AND    MEMORANDA.  315 

of  the  tubes  on  the  under  surface,  where  their  extremities  form  the 
basiclia  and  basidiospores,  others  bend  upwards  to  the  upper  surface  of 
the  pileus,  above  which  their  delicate  hyaline  extremities  project  to 
the  extent  of  from  0  •  025  to  0  •  05  mm.,  and  then  divide  into  two  or 
three  branches,  each  of  which  produces  a  spore  at  its  extremity.  In 
the  species  named,  these  spores  resemble  in  every  respect  the  ordinary 
purple-brown  spores  produced  within  tlic  tubes  on  the  under  side  of  the 
pileus,  while  in  other  sj)ecies  they  present  some  difference.  The 
sporophores  are  usually  somewhat  crooked,  and  after  producing  the 
spores,  disappear  completely,  leaving  no  trace  behind,  the  spores 
alone  remaining  as  a  reddish-brown  coating  on  the  upj)er  side  of  the 
pileus. 

Change  of  Colour  in  the  Spores  of  Fungi. —  Schulzer  records* 
a  singular  instance  of  the  spores  of  a  fungus  which  he  considered 
closely  allied  to  Agaricus  {^Hyplioloma)  cascus,  Fr.,  changing  their 
colour  beneath  his  eyes  from  purple-brown  to  black.  The  observation 
was  made  while  testing  the  correctness  of  Fries's  statement  that  the 
colour  of  fungus-spores  appears  to  vary  according  to  the  colour  of  the 
substance  on  which  they  lie,  a  statement  he  was  unable  to  confirm. 

Fungi  found  within  the  Shell  of  the  Egg. — Dr.  0.  E.  E.  Zimmer- 
mann  contributes  to  the  '  Bericht  der  naturw.  Gesellsch.  in  Chemnitz 
(1878)  a  complete  history  of  the  various  fungi  which  induce  jiutrefac-' 
tion  of  the  egg.  The  attack  of  the  fungus  is  sometimes  indicated  by 
small  green,  yellow,  yellowish  red,  or  brown  spots  on  the  shell,  with 
internal  projections  into  the  albunien  ;  or  by  yellow  or  greenish-yellow 
spots  in  the  albumen  itself,  which  then  becomes  a  slate-coloured  fluid, 
while  the  yolk  passes  into  tough  blackish  lumps,  accompanied  by  the 
offensive  odour  of  sulphuretted  hydrogen.  These  changes  are  caused 
by  various  fungi.  Frequently  there  is  found  only  a  sterile  thin-walled 
colourless  or  thick-walled  olive-green  mycelium,  the  cells  of  which 
readily  separate  from  one  another,  or  a  mueor-myeelium  (probably 
Mucor  racemosus)  propagating  by  gemmation.  Among  fructifying 
fungi,  chiefly  in  the  air-chamber  at  the  larger  end,  were  found  Peni- 
cillium  glaucum,  Aspergillus  glaucus,  Stysanus  stemonitis,  Echinobotryum 
atrum,  Mucor  stolonifer,  a  Botrytis,  and  a  new  species,  Macrosporhim 
verruculosum,  as  well  as  bacteria,  especially  Bacterium  termo  and  Ba- 
cillus suhtilis,  together  with  torula-cells,  and  others  similar  to  those  of 
Oidium  lactis.'\ 

Fungi  parasitic  on  the  Cabbage.  —  Under  the  title  '  Plasmo- 
diophora  Brassicfe,  Urheber  der  Kohlpflanzen  -  Hernie,'  |  Woronin 
publishes  a  treatise,  illustrated  with  six  plates,  in  which  he  describes 
the  cause  of  the  "  club  "  disease  so  common  on  the  root  of  the  cabbage. 
It  is  a  fungus,  to  which  he  gives  the  name  Plasmodiophora,  the  simplest 
form  hitherto  known  of  the  Myxomycetes.  It  consists  of  a  minute 
mass  of  protoplasm  or  plasmodium,  which  is  never  enclosed  within 
a  cellulose  envelope,  but  breaks  up  eventually  into  a  great  number  of 

*  '  Flora,'  xxxvi.  (1878)  471. 

t  '  Hedwi^ia,'  xvii.  (1878)  190. 

X  '  Jahrl.  f.  wiss.  Bot.,'  xi.  (1878)  548. 


316  NOTES   AND   MEMORANDA. 

small  spores,  each  of  which  becomes  a  myxamceba.  These  penetrate 
into  the  tissue  of  the  root,  and  develop  into  a  new  plasmodium,  though 
whether  by  the  coalescence  of  a  number  of  myxamoebae  is  still  un- 
certain. In  addition  to  the  Plasmodiophora,  Woronin  found  in  the 
diseased  roots  a  new  Chytriclium  (C.  Brassicce),  propagated  by  zoo- 
spores. The  zoosporangium  has  a  globular  base,  and  is  elongated 
above  into  a  hmg  neck,  which  oj)ens  to  allow  the  escape  of  the 
zoospores,  usually  outside  the  tissue  of  the  host.  Eesting-spores 
were  also  observed,  probably  formed,  as  in  other  Chytridiaceaj,  by  the 
coalescence  of  two  zoospores,  though  Woronin  has  not  at  present  been 
able  actually  to  detect  this  process.  Similar  malformations  found  on 
the  roots  of  many  other  plants,  especially  Leguminosaa,  are  probably 
due  to  the  attacks  of  fungi  of  the  same  nature. 

Fungus  Disease  in  Lettuces  (Peronospora  gangliiformis). — Eefer- 
ring  to  this  subject  (see  page  167),  MM.  Bergeret  and  Moreau  have 
found  *  that  water  very  slightly  acidulated  with  nitric  acid  constitutes 
a  good  remedy  for  the  disease.  This  solution  has  the  double  advan- 
tage of  being  a  manure  for  the  soil,  and  a  poison  to  the  fungus;  or  at 
least  a  means  of  arresting  its  development. 

Fungi  of  Stalactites.  —  Fungi  play  an  important  and  hitherto 
unnoticed  part  in  stalactitic  distortion.  In  an  account  f  of  an  explo- 
ration of  the  Luray  Cavern,  Virginia,  U.S.,  Mr.  H.  C.  Hovey  says 
that  his  attention  was  called  to  numerous  fine  elastic  bristles  growing 
on  stalactites  and  other  kinds  of  dripstone  in  all  parts  of  the  cavern. 
Each  carried  a  little  ball  at  its  extremity  usually  enveloped  by  a 
globule  of  water,  and  he  further  observed  that  the  conditions  often 
favoured  a  thin  deposit  of  the  carbonate  of  lime  on  these  bristles,  so 
that  their  shape  remained  after  the  substance  had  decayed.  Many  of 
these  black  setae  and  white  filaments  were  examined  by  the  Microscope, 
and  the  gradations  were  traced  from  the  finest  hairs  up  to  great  knots 
and  tangled  outgrowths. 

This  fungus  is  a  new  species  of  Mucor,  to  which  he  gives  the  name 
of  M.  stalactitis.  Sporangia  globose,  membranaceous,  dehiscing  by  a 
fissure,  terminating  threads ;  sporidia  sub-globose  and  separating ; 
flocci  tubular,  indistinctly  partitional,  sometimes  branching  at  the 
base,  but  never  at  the  apex.  Specific  marks :  Sub-solitary  threads ; 
sporangia  simple  ;  height  -^^  to  i  inch ;  colour  dark  olive-green. 

Conidial  Fructification  of  Fumago. — W.  Zopf  has  written  a  trea- 
tise on  this  subject,!  in  which  he  showed  that  the  conidial  fructification 
of  this  fungus  is  obtained  only  when  it  is  cultivated  on  a  substratum 
of  a  highly  nourishing  character.  When  the  supply  of  nutriment  is 
deficient,  thi-ee  forms  may  be  obtained ;  the  yeast-like  budding-plants, 
in  a  fluid ;  the  mycoderma  and  chalara-like  forms,  on  the  surface  of  a 
fluid ;  and  mycelial  plants  bearing  micro-gonidia  (aerial  form),  on  a 
solid  dry  substratum.  He  had  never,  notwithstanding  long  trials, 
been  able  to  obtain  the  large-spored  pycnidia  or  the  asci. 

*  'Comptes  Eendus,'  Ixxxviii.  (1879)  429. 
t  '  Scientific  American '  (1879). 
t  'Hedwigia,'  xvii.  (1878)  100. 


NOTES   AND    MEMORANDA.  317 

Homology  of  the  "Nucule"  of  Characeae. —  The  female  organ 
of  Charaeese,  variously  termed  nucule,  oogonium,  and  archegonium, 
has  been  treated  by  A.  Braun,  Sachs,  and  others,  as  a  metamor- 
phosed shoot ;  whence  the  ordinary  German  appellation  of  "  Sporen- 
sprosschen."  In  '  Flora'  *  Celakovsky  gives  reasons  for  regarding  the 
enclosed  (behiillte)  oogonium,  as  he  prefers  to  call  it,  as  homologous 
morphologically  with  the  globule  or  male  organ,  viz.  a  metamorphosed 
foliar  structure  or  portion  of  a  leaf,  and  consequently  homologous 
also  with  the  ovule  of  flowering  plants. 

Arrangement  of  the  Cells  in  the  flat  Prothallia  of  Ferns. — In 
a  series  of  observations  on  this  subject,  j  Dr.  Prantl  states  that  the  first 
divisions  which  convert  a  filament  into  a  plate  of  cells  are  not  deter- 
mined by  its  position  with  respect  to  light  nor  with  respect  to 
gravitation  ;  the  subsequent  position  of  the  plate  at  right  angles  to  the 
incident  light  being  the  result  of  torsion.  In  those  prothallia  which 
possess  a  meristem,  its  cells  are  distinguished  by  their  smaller  size, 
denser  protoplasm,  and  more  frequent  division ;  these  prothallia, 
therefore,  grow  more  rapidly  than  those  that  are  ameristic.  The 
absence  of  meristem  is  generally  the  result  of  a  deficiency  either  of 
light  or  of  water.  Archegonia  are  formed  especially  in  the  neighbour- 
hood of  a  meristem,  from  cells  which  have  just  been  produced  from 
the  meristem,  and  therefore  usually  arise  in  acropetal  succession.  The 
absence  of  archegonia  is  generally  due  to  the  want  of  meristem.  The 
antheridia  of  ferns  are,  on  the  other  hand,  trichomes,  and  may  spring 
from  any  of  the  older  cells,  and  may  consequently  occur  on  ameristic 
prothallia.  Prantl  completely  confirms  Sachs's  statement  that  the  new 
division-wall  is  always  nearly  vertical  to  that  from  which  it  springs ; 
and  this  is  even  the  case  in  the  wedge-shaped  apical  cell. 

The  position  and  extent  of  the  meristem  vary  in  difierent  pro- 
thallia. In  some  it  occupies  the  larger  part  or  even  the  whole  of  the 
free  margin,  and  may  then  be  termed  marginal  meristem.  In  others  it 
occupies  only  a  small  portion  of  the  margin  near  the  apex,  and  is  then 
an  apical  meristem.  This  meristem  passes  gradually  into  permanent 
tissue,  there  being  no  sharp  line  of  demarcation  between  them.  A 
single  cell  of  the  apical  meristem  which  possesses  the  merismatic  pro- 
perty in  excess,  and  every  division  of  which  helps  to  form  the  curve 
of  the  margin,  is  known  as  the  apical  cell ;  but  it  is  often  a  matter  of 
great  difficulty  to  distinguish  the  apical  cell  from  its  neighbours.  The 
absolute  increase  of  the  cells  Prantl  found  to  be  less,  the  smaller  the 
size  of  the  cells,  and  consequently  least  in  the  meristem ;  while  the 
increase  in  proportion  to  the  size  of  the  cell  is  greatest  in  the 
meristem,  and  sometimes  gi'eatest  of  all  in  the  apical  cell  itself. 

Apogamous  Ferns  and  the  Phenomenon  of  Apogamy  in  general. 
— Professor  A.  De  Bary,  in  an  article  bearing  the  above  title,  in  the 
'  Botanische  Zeitung,'  |  gives  the  results  of  his  observations  on  non- 
sexual reproduction  in  ferns  as  first  described  in  1874  by  Dr.  Farlow. 

*  '  Flora,'  xxxvi.  (1878)  p.  49  et  sea. 

t  Ibid.,  497. 

t  July  19th,  1878,  et  seq. 


318  NOTES    AND    MEMORANDA. 

It  was  tlicn  shown  that,  in  some  cases,  the  prothalli  of  Pteris  cretica, 
instead  of  the  usual  growth  from  a  fertilized  archegonium-cell,  pro- 
duced ordinary  buds,  from  which  the  new  fern  plant  developed  without 
any  sexual  action  whatever.  The  observations  now  published  by  Da 
Bary  were  made  with  the  intention  of  ascertaining  more  in  detail  the 
frequency  with  which  the  non-sexual  mode  of  reproduction  occurred 
in  ferns,  and  its  relation  to  similar  processes  in  other  groups  of  the 
vegetable  kingdom. 

He  found,  on  sowing  the  sj)ores  of  Pteris  cretica,  obtained  both  from 
ciiltivated  jilants  of  that  species  and  from  forms  which  grew  wild  in 
Italy,  that,  in  all  cases,  the  prothalli  produced  only  the  non-sexual 
buds,  to  which  he  gives  the  name  of  "  Farlowsche  Sprossung."  In  the 
few  cases  where  antheridia,  archegonia,  and  the  normal  embryonic 
development  ajiparently  occurred,  he  found,  by  watching  the  further 
development  of  the  fern,  that  the  prothalli  were  not  those  of  Pteris 
cretica,  but  came  from  the  spores  of  other  species  which  had  acci- 
dentally found  their  way  into  the  cultures.  Of  the  ditferent  species 
studied  by  De  Bary,  in  thirty-four,  exclusive  of  varieties,  only  the 
normal  development  by  embryo-formation  in  the  central  cell  of  the 
archegonium  was  observed  ;  in  three,  Aspidium  Filixmas  var.  cristafum., 
Aspidium  falcatum,  and  Pteris  cretica,  only  the  non-sexual  budding. 
The  prothalli  of  Pteris  cretica  may  or  may  not  bear  antheridia.  When 
present,  they  have  the  same  structure  as  in  the  typical  PolypodiacecB. 
In  by  far  the  majority  of  cases  there  are  no  traces  of  archegonia,  even 
in  a  rudimentary  condition.  Out  of  hundreds  of  cases,  only  seven 
were  found  with  archegonia,  and  they  all  aborted.  Aspidium  Filix- 
mas perfectly  resembles  Pteris  cretica  in  the  distribution  of  antheridia 
and  archegonia,  but  in  Aspidium  falcatum  archegonia  occurred  in  at 
least  25  or  30  per  cent,  of  the  prothalli.  Although  in  the  cases 
observed  they  had  all  aborted,  De  Bary  thinks  it  possible  that  cases 
may  occur  in  which  the  normal  embryo-formation  takes  place,  which 
is  hardly  possible  in  the  two  species  first  named. 

The  budding  process,  in  all  three  cases,  consists  in  the  formation 
of  a  protuberance  on  the  under  surface  of  the  prothallus,  from  which 
grow  a  first  leaf,  root,  and  stem-bud  as  in  the  normal  embryo-formation, 
although  their  relative  position  and  date  of  development  vary.  The 
protuberance  is  generally  found  just  at  the  back  of  the  sinus,  where 
the  fertilized  archegonium  normally  occurs.  Variations  were  seen  in 
which  the  first  leaf  grew  from  the  upper  surface  of  the  prothallus, 
and,  at  times,  two  leaves  were  produced,  one  on  the  upper  and  one  on 
the  lower  surface.  Secondary  forms  may  be  produced  upon  elon- 
gations of  the  lateral  lobes  of  the  prothallus.  Some  of  the  more 
l^eculiar  forms  are  figiired  in  the  plate  which  accompanies  the  article. 
In  the  three  species  under  consideration,  as  the  normal  reproduction 
by  an  embryonal  growth  has  been  lost,  and  another,  non-sexual  form 
of  reproduction  has  taken  its  place,  we  may  infer  tbat  they  have 
descended  from  some  ancestral  form  in  which  the  sexual  mode  of 
reproduction  existed.  This  is  illustrated  by  the  case  of  Aspidium 
Filix-mas  var.  cristatum,  which  is  undoubtedly  derived  from  the 
typical  Aspidium    Filix-mas,  in    which    only  sexual   reiu'oduction    is 


NOTES   AND    MEMORANDA.  319 

known.  If,  however,  we  adopt  the  view  recently  advanced  by  Prings- 
heim,  that  ferns  were  originally  composed  of  "  Bionten,"  some  of 
which  were  sexual  and  some  non-sexual,  and  which  alternate  more  or 
less  regularly  with  one  another,  we  must  consider  that,  instead  of 
having  acquired  a  new  power,  the  ferns  which  rein'oduce  by  budding 
represent  a  case  of  atavism. 

De  Bary  gives  the  name  of  Apogamy  to  this  substitution  of  some 
other  form  of  reproduction  in  cases  where  the  power  of  sexual  re- 
production has  been  lost.  This  condition  is  found  in  all  parts  of 
the  vegetable  kingdom,  and  occurs  in  single  species  whose  nearest 
allies  reproduce  normally.  Apogamy  is  of  three  kinds :  apogeny, 
where  the  function  of  both  male  and  female  organs  is  destroyed  ; 
apogyny,  loss  of  reproductive  power  in  the  female,  apandry,  in  the 
male  organ. 

Chara  crinifa  is  a  good  instance  of  apandry  with  parthenogenesis, 
that  is  of  regular  embryo-formation  from  an  unfertilized  ovule.  The 
female  of  this  species  is-  alone  known  in  northern  Europe,  yet  it  fruits 
abundantly.  It  has  been  studied  by  De  Bary  in  specimens  artificially 
grown  in  his  laboratory ;  and  there  is  no  doubt  that  here  it  is  not  a 
question  of  the  partial  suppression  but  of  the  total  loss  of  the  male 
organs.  In  ferns  we  have  the  best  instances  of  a  substitution  of  a 
shoot  for  the  normal  sexual  growth.  To  the  same  category  belong 
some  of  the  mosses  usually  called  sterile,  that  is  destitute  of  capsular 
growths.  In  the  mosses,  however,  it  is  a  question  not  yet  settled 
whether  there  is  a  total  loss  or  only  a  partial  suppression  of  sexual 
reproduction. 

In  Funkia  and  Allium  fragrans,  in  the  seeds  of  which  Strassburger 
discovered  adventive  embryos,  we  have  something  similar  to  the 
apogamous  ferns  ;  first,  in  the  presence  of  apparently  regularly  formed 
but  f  unctionless  female  organs ;  secondly,  in  the  presence  of  apjia- 
rently  active  pollen;  and,  thirdly,  in  the  substitution  of  adventive 
embryos  for  the  regular  embryo-formation.  Citrus  and  Ccelebogyne,  in 
which  Strasburger  also  found  adventive  embryos,  probably  belong  to 
the  same  class  as  Allium  and  Funkia,  as  may  also  species  like 
Euonymus  latifoUus,  many  ArcUsice,  &c.,  in  which  polyembryony  often 
occurs.  To  these  are  to  be  added  the  numerous  species,  varieties,  and 
races  of  cultivated  plants  which  rarely  produce  seeds,  but  instead 
have  a  correspondingly  richer  reproduction  by  shoots.  If,  as  seems 
tolerably  certain,  sexual  reproduction  is  requisite  to  the  constant 
propagation  of  species,  we  must  regard  apogamy  as  a  degenerate  con- 
dition, in  which  the  conditions  of  propagation  are  imfavourable.  In 
this  connection,  however,  we  must  not  overlook  the  fact  that  in  species 
with  budding  or  non-sexual  reproduction  this  oflspring  is  produced  in 
surj)assing  profusion.* 

Apogamy  in  Isoetes.  —  The  phenomenon  of  apogamy  appears, 
according  to  the  statement  of  K.  Goebel,-j-  to  extend  also  to  Isoetes. 
In  two  species,  I.  lacustris  and  echinospora,  he  observed,  on  a  large 
number  of  specimens,  that  both  macrospoiaugia  and  microsporangia 

*  '  Amer.  Jour.  Sci.  and  Arts,'  xvi.  (1878)  401. 
t  '  Botauisclie  Zeitung,'  xxxvii.  (187i.»)  1. 


320  NOTES    AND    MEMORANDA. 

were  replaced  by  young  plants,  occupying  the  same  position,  springing, 
namely,  from  the  fovea  of  the  leaf.  These  were  not  the  product  of 
the  germination  of  the  nmcrospores  within  their  sporangium,  the 
macrosporangium  being  entirely  suppressed.  In  their  rudimentary 
stage  these  non-sexually  produced  plants  are  simply  conical  emer- 
gences, altogether  resembling  the  rudiments  of  sporangia,  but  they 
gradually  develop  into  plants  with  ordinary  leaves.  These  shoots 
are  not  analogous  to  the  bulbils  which  characterize  many  classes  of 
vascular  cryptogams,  such  as  Lycopodiacese  and  Ferns,  in  which  the 
Isoetese  appear  to  be  exceptionally  entirely  deficient,  a  phenomenon 
closely  connected  with  the  absence  of  branching.  It  is  rather  an 
instance  of  "  apogamy  "  carried  out  to  its  most  complete  stage,  namely, 
the  complete  suppression,  not  only  of  the  sexual  organs,  but  of  the 
entire  sexual  generation. 

MICEOSCOPY,  &c. 

Microscopes  with  Swinging  Tailpiece.  —  This  addition  to  the 
Microscope  has  been  revived  within  the  last  few  years,  and  its  novelty 
having  been  the  subject  of  some  discussion,  we  have  referred  to  the 
provisional  specification  (not  further  proceeded  with)  of  Mr.  Thomas 
Grubb,  at  the  office  of  the  Commissioners  of  Patents,  in  July,  1854. 
The  nature  of  the  invention  was  thereby  declared  to  "  consist  in  the 
addition  of  a  graduated  sectoral  arc  to  Microscopes  concentric  to  the 
plane  of  the  object  '  in  situ,'  on  which  either  a  prism  or  other  suitable 
illuminator  is  made  to  slide,  thereby  producing  every  kind  of  illu- 
mination required  for  microscopic  examination,  and  also  the  means 
of  registering  or  applying  any  definite  angle  of  illumination  at 
pleasure." 

On  1st  August,  1876,  letters  patent  were  granted  to  Mr.  John 
Stuart  (on  behalf  of  Mr.  Zentmayer,  of  Philadelphia)  for  improve- 
ments in  Microscopes  by  means  of  which  the  sub-stage  carrying  the 
illuminating  apparatus  and  accessories  (together  with  the  mirror  if 
desired)  and  also  the  object  stage  may  be  placed  at  any  required 
angle  in  relation  to  the  optical  axis  of  the  Microscope  and  object- 
glass,  and  also  at  an  angle  in  relation  to  each  other  for  the  purpose  of 
more  conveniently  illuminating  and  viewing  the  object  under  exami- 
nation, more  particularly  when  oblique  illumination  is  required. 

The  iavention  consists  of  a  method  by  means  of  which  the  stem 
which  carries  the  sub-stage  and  the  mirror  may  be  made  to  swing 
sideways  to  the  right  or  left,  either  below  or  above  the  stage  on  a 
centre  having  for  its  axis  of  rotation  a  line  in  the  plane  of  the  object 
on  the  stage  intersected  by  the  optical  axis,  that  is,  a  line  passing 
through  the  centre  of  the  body  and  the  object-glass  of  the  Microscope. 
The  stage  is  also  made  to  turn  independently  on  a  separate  pivot, 
having  for  its  axis  of  rotation  the  aforesaid  line. 

The  figure  represents  in  sectional  elevation  a  portion  of  the 
Microscope. 

S  is  the  limb  carrying  the  body  with  coarse  and  fine  adjustments. 
A  is  the  stem  which  carries  the  sub-stage  B,  and  mirror  if  required. 
A  is  attached  to  S  by  the  sleeve  or  socket  I,  clamped  by  the  nut  J, 


NOTES   AND    MEMORANDA. 


321 


ancT  on  I,  A  may  be  swung  sideways  in  either  direction  to  the  right 
or  left  either  below  or  above  the  stage,  the  axis  of  revolution  of  which 
is  the  line  X  Y,  that  is,  a  line  in  the  plane  of  the  object  to  be  viewed 
on  the  stage  C,  intersected  by  the  optical  axis  of  the  instrument,  that 
is,  the  line  N  0,  passing  through  the  centre  of  the  body  and  the 


object-glass  of  the  microscope.  The  stage  C  is  also  attached  to  S  by 
the  pin  C\  terminated  by  the  screen  C^,  which  pin  passes  through 
the  centre  of  the  socket  I,  and  turns  therein  so  that  the  stage  C  may 
be  made  to  turn  in  either  direction  in  conjunction  with  or  independent 
of  A,  the  axis  of  its  revolution  being  also  the  line  X  Y. 

By  this  arrangement  the  stage  C  and  the  stem  A  may  be  set  at  an 
angle  to  the  axis  of  the  microscope  either  below  or  above  X  Y,  inter- 
secting the  plane  of  the  object  to  be  viewed  and  also  relative  to  each 
other,  and  when  so  set  the  stage  C  may  be  clamped  at  the  desired 
angle  by  the  nut  D  on  the  screw  C^,  acting  on  S  and  the  collar  K. 

The  specification  then  proceeds  (in  the  language  usual  in  such 
cases) : — 

"  Having  thus  particularly  described  and  ascertained  the  nature 
of  the  said  invention  and  the  manner  in  which  the  same  may  be  per- 
formed or  carried  into  effect,  I  would  remark  that  I  am  aware  that 
microscopes  have  been  heretofore  made  in  which  a  stem  or  tail-piece 
has  been  applied  so  as  to  swing  from  a  centre  situate  below  the  plane 
of  the  object  stage,  and  therefore  no  claim  is  herein  made  in  general 

VOL.  II.  Y 


322  NOTES   AND   MEMOKANDA. 

to  a  stem  or  tail-piece  made  so  as  to  bo  swung  in  this  position,  but 
the  invention  which  I  consider  to  be  novel  and  therefore  desire  to  be 
secured  to  me  by  the  herein  in  part  recited  letters  patent,  is — 

"  First.  The  making  the  stem  A,  which  carries  the  sub-stage  B, 
to  swing  to  the  right  or  to  the  left  either  below  or  above  the  stage  of 
the  microscope  on  a  centre  sleeve  socket  or  joint  I,  the  axis  of  revo- 
lution whereof  is  the  line  X  Y,  in  the  plane  of  the  object  to  be  viewed 
on  the  stage  C,  intersected  by  the  optical  axis,  that  is,  the  line  N  O, 
passing  through  the  centre  of  the  body  F  and  the  object-glass  of  the 
microscope,  substantially  as  described  and  shown  in  the  drawing. 

"  Secondly.  The  arrangement  herein  described  and  shown  in  the 
drawing  for  enabling  the  object-stage  C  to  swivel  or  turn  on  a  centre 
or  pivot  within  the  sleeve  or  socket  I,  so  that  the  axis  of  rotation  of 
the  object-stage  0  shall  be  from  the  same  centre  as  that  on  which  the 
stem  or  part  A  turns  to  the  right  or  left,  and  the  method  of  clamping 
the  object-stage  C  in  the  required  angle,  as  herein  described  and  shown 
in  the  drawings." 

"Penetration"  of  Wide-angled  Objectives.  —  It  has  been  ob- 
jected to  wide-angled  lenses  that  they  possess  less  penetrating  power, 
or,  more  jiroperly,  less  depth  of  focus  than  narrow-angled  lenses  ;  that 
is  to  say,  that  the  layer  of  an  object,  that  can  be  seen  without  change 
of  focus,  is  thinner  with  wide  than  with  narrow-angled  lenses. 

Dr.  Blackham,  the  President  of  the  Dunkirk  (U.S.)  Microscopical 
Society,  says  that  if  this  were  true  it  would  be  an  argument  in  favour 
of  the  wide-angled  lenses,  instead  of  against  them  ;  in  reality,  however, 
it  does  not  depend  upon  the  aperture,  but  is  only  residual  spherical 
aberration,  which  can  be  left  in  and  distributed  in  a  wide-angled  lens 
as  well  as  in  a  narrow-angled  one.  This  will  be  readily  api^reciated 
upon  considering  the  action  of  an  uncorrected  plano-convex  lens  of 
crown  glass.  The  rays  from  the  nearer  surface  of  the  object  which 
impinge  upon  the  peripheral  portions  of  the  lens  would,  if  the  lens 
were  free  from  spherical  aberration,  be  brought  to  a  focus  further 
back  than  those  from  the  further  surface  of  the  object  which  impinge 
upon  the  central  portions  of  the  lens.  As  it  is,  however,  they  are 
brought  to  the  same  focus,  by  reason  of  the  spherical'  aberration. 
Such  a  lens  has  a  good  deal  of  penetrating  power,  or  depth  of  focus, 
but  its  definition  is  not  satisfactory.  The  same  holds  true  of  all 
objectives  possessed  of  penetrating  power,  whatever  their  angular 
aperture.  The  only  legitimate  method  of  obtaining  depth  of  focus 
or  "  penetration "  is  by  increasing  the  anterior  conjugate  focus  or 
frontal  distance,  so  that  the  thickness  of  the  layer  that  it  is  desired  to 
see  on  each  side  of  the  true  focal  plane  may  be  relatively  small. 
Thus  a  1-inch  objective  with  an  anterior  focus  of  'SIT  of  an  inch 
will  bear  amplification  up  to  400  diameters,  and  at  that  power  might 
properly  show,  with  reasonable  clearness,  a  layer  of  the  object  on 
each  side  of  the  true  focal  plane  much  thicker  than  that  which  a  one- 
fifth  with  only  -018  of  an  inch  of  anterior  focus  ought  to  show  at  the 
same  amplification.  It  is  perhaps  true  that,  by  skilful  management, 
the  residual  sjiherical  aberration  can  be  so  distributed,  that  several 
planes  of  an  object  can  be  in  view  at  once ;  but  this  is  always  at  the 


NOTES   AND    MEMORANDA.  323 

sacrifico  of  definition,  and,  as  the  better  the  image  the  more  notice- 
able do  errors  resulting  from  this  plan  of  overlapping  several  of  them 
become,  wide-angled  glasses  show  the  defects  of  this  jilan  more  mark- 
edly than  narrow-angled  lenses,  whence  has  arisen  the  fallacy  that 
narrow-angled  lenses  are  possessed  of  an  inherent  property  of  "  pene- 
tration "  and  a  residual  error  has  been  lauded  as  a  virtue.* 

Process  for  Measuring  the  Solid  Angles  of  Microscopic  Crys- 
tals.— In  the  '  Bulletin  de  la  Societe  Mineralogique  de  France ' 
(1878,  No.  4,  p.  68)  M.  Thoulet  gives  the  following  method  for 
measuring  the  solid  angles  of  microscopic  crystals:  — 

If,  in  a  tetrahedron,  we  know  the  lengths  of  the  six  edges,  we  can 
ascertain  the  angles  of  the  faces  surrounding  the  same  summit,  and 
can  consequently  resolve  the  spherical  triangle  whose  sides  are  respec- 
tively the  angles  of  the  faces  of  the  tetrahedron,  and  whose  angles  are 
the  dihedral  angles  of  the  edges  of  this  same  tetrahedron. 

We  place  the  crystal  (which  may  be  isolated  or  contained  in  a  thin 
plate  of  rock)  in  any  given  position  Tinder  the  Microscoi>e,  and  choose 
four  special  points,  two  on  the  edge,  and  the  others  respectively  on 
one  and  the  other  of  the  two  planes  whose  angle  is  to  be  measured. 
By  means  of  the  fine  adjustment  of  the  microscope,  we  successively 
bring  into  focus  each  of  these  summits,  and  note  the  vertical  displace- 
ment in  each  case  by  the  milled  head. 

Without  moving  the  crystal,  we  replace  the  eye-piece  by  a  camera 
lucida,  and  make  a  drawing  of  the  crystal,  marking  very  accurately  by 
pricks  the  position  of  the  four  j^oints ;  then  the  crystal  is  replaced  by 
a  stage  micrometer,  which  will  make  a  scale  of  the  drawing  to  be 
made. 

We  now  possess  all  the  data  necessary  to  calculate  the  solid  angle. 
Each  of  the  sides  of  the  tetrahedi-on  is  determined :  1st,  by  its  hori- 
zontal projection  on  the  drawing ;  2nd,  by  the  difierence  in  the  vertical 
height  of  its  two  extremities,  as  indicated  by  the  fine  adjustment. 

The  rest  of  the  work  is  only  a  trigonometrical  calculation  of  three 
rectilinear  triangles,  whose  three  sides  are  known,  and  of  which  one 
of  the  angles  has  to  be  found,  and,  finally,  the  calculation  of  a  sphe- 
rical triangle  whose  three  sides  are  known,  and  one  of  the  angles  of 
which  is  to  be  found. 

Instead  of  drawing  the  whole  crystal,  it  is  evident  that  it  would 
suffice  to  note  the  four  essential  points ;  the  complete  drawing,  how- 
ever, allows  a  subsequent  verification,  which  is  often  necessary,  and, 
besides,  enables  us  to  decide  as  to  the  crystallographic  notations  to  be 
given  to  the  crystalline  face. 

The  solid  angles  of  crystals  having  dimensions  less  than  y-^^  of  a 
millimetre  can  be  measured  to  less  than  a  degree  by  this  method.f 

Method  of  Isolating  the  Connective-Tissue  Bundles  of  the  Skin. 
— Dr.  George  Thin,  in  a  paper  communicated  to  the  Eoyal  Society,;]: 
describes  the  method  he  has  made  use  of  for  this  object. 

*  From  a  paper  read  by  Dr.  Blackham  before  the  Indianapolis  Congress. 
Cf.  a  French  translation  m  '  Journal  de  Microgranhie,'  iii.  (1879). 
t  '  Bull.  Soe.  Belg.  de  Micr  ,'  v.  (1878)  6. 
i  '  Proc  E.  Soe.,'  xxviii.  (1879)  251. 

Y    2 


32 1  NOTES    AND    MEMORANDA. 

By  the  term  hmdle,  or  secondary  bundle,  Dr.  Thin  designates  the 
ordinary  bundle  of  authors,  which  is  more  or  loss  consiiicuous  in  all 
preparations  of  skin,  and  which  is  analogous  in  structure  and  size 
to  the  bundles  as  usually  described  and  figured  in  tendon-tissue.  The 
element  described  by  Eollett  as  "  connective-tissue  fibre  "  he  desci-ibes 
as  primary  bundle,  to  distinguish  it  more  markedly  from  the  fibrillfe 
which  compose  it.  When  groups  of  secondary  bundles  are  isolated, 
each  group  being  composed  of  several  secondary  bundles,  he  terras 
the  group  a  tertiary  bundle. 

These  elements  can  be  isolated  by  first  saturating  the  cerium  with 
chloride  of  gold  solution,  and  then  macerating  the  tissue  in  acids. 
Portions  of  skin,  with  a  thick  layer  of  the  panniculus  adiposus,  were 
taken  fresh  from  the  mamma  of  a  middle-aged  woman,  which  had 
been  removed  for  a  tumour  of  the  gland,  the  portions  of  skin  chosen 
being  well  clear  of  diseased  tissues.  The  stretched  skin  was  pinned 
down  to  a  cork  board,  the  under  surface  uppermost,  and  then  saturated 
with  ^  per  cent,  chloride  of  gold  solution.  From  time  to  time  dif- 
ferent thicknesses  of  the  fatty  layer  were  removed  as  the  solution  had 
had  time  to  penetrate  into  the  tissue,  until,  finally,  the  deejjer  layer  of 
the  cutis  proper  was  laid  bare.  The  tissue,  still  extended,  was  then 
placed  in  fresh  gold  solution  for  several  hours.  The  object  of  the 
manoeuvre  was  to  secure  the  penetration  of  the  fluid  through  the 
bundles,  whilst  these  were  still  extended  in  their  natural  condition. 

After  a  due  action  of  the  gold,  the  skin  was  cut  into  small  pieces, 
which  were  then  treated  by  acetic  acid,  and  then  the  strength  of  the 
acetic  acid  raised  to  20  per  cent,  of  the  ordinary  concentrated  acetic 
acid  of  commerce.  Other  portions  were  treated  by  formic  acid.  Some 
successful  preparations  were  obtained  from  portions  macerated  first  for 
a  few  days  in  a  mixture  of  one  part  formic  acid,  of  specific  gravity 
1  •  020,  and  one  of  water,  and  then  in  the  undiluted  acid  for  some  days 
longer,  but  a  strict  adherence  to  these  strengths  was  not  found  necessary. 

Portions  of  the  corium  thus  prepared  were  teased  out  in  glycerine 
and  examined  directly  or  after  staining  by  different  dyes.  Staining  by 
picric  acid  was  found  very  advantageous. 

In  this  way  he  was  able  to  isolate  in  a  condition  favourable  for 
study  the  primary,  secondary,  and  tertiary  bundles.  Generally  speak- 
ing, although  not  invariably,  the  tertiary  and  secondary  bundles  were 
best  seen  in  the  tissues  macerated  in  acetic  acid,  and  the  secondary 
and  primary  bundles  in  those  treated  by  formic  acid. 

Numerous  elastic  fibres  were  isolated  by  both  methods,  the  finest 
fibres  more  particularly  in  the  formic  acid  preparation. 

Various  methods  have  been  recommended  by  histologists  for  the 
demonstration  of  the  ultimate  fibrillte  of  fibrous  tissue,  chiefly  with 
reference  to  those  of  tendon  bundles.  Judging  by  the  figures  pub- 
lished in  histological  works,  the  fibrillfe  of  the  cutis  bundles  are. 
Dr.  Thin  thinks,  very  seldom  seen  ;  the  appearances  usually  observed 
in  skin  hardened  by  chromic  acid  and  alcohol  are  unfitted  for  a  study 
of  the  fibrillfe.  In  such  specimens  the  bundles  are  more  or  less  broken 
up,  but  the  individual  fibrillfe  are  not,  as  a  rule,  isolated.  He  found, 
however,  that  they  were  well  shown  by  the  following  method  : — A 


NOTES   AND   MEMOEANDA.  325 

portion  of  fresh  skin,  with  the  panuiculus  adiposus  attached,  was 
pinned  to  a  piece  of  cork  in  the  manner  already  described,  and  treated 
in  the  same  way,  with  the  exception  that  this  time  glycerine,  instead 
of  chloride  of  gold  solution,  was  used  for  saturation.  When  the 
saturated  cutis  tissue  had  been  laid  bare,  the  whole  was  placed  in 
glycerine,  and  allowed  to  remain  in  it  for  several  days.  Small  portions 
were  then  teased  out  in  glycerine,  stained  by  picro-carminatc  of 
ammonia,  and  examined  in  glycerine.  In  such  preparations  the 
secondary  bundles  were  found  isolated,  the  contours  of  the  primary 
bundles  not  being  preserved.  In  the  secondary  bundles  the  fibrillsB 
were  seen  more  or  less  distinctly,  in  some  of  them  with  perfect  dis- 
tinctness. 

Process  for  Preparing  the  Embryos  of  Fishes. — The  ova  of  the 
Salmonidfe  are  generally  employed  by  embryologists  for  the  study  of 
the  development  of  osseous  fishes.  It  is  difficult  to  observe  them  in 
the  fresh  state,  either  whole,  by  transmitted  light,  on  account  of  the 
thickness  of  their  envelope,  or  after  having  opened  them,  in  conse- 
quence of  the  small  consistency  of  the  germ,  especially  at  the  com- 
mencement of  the  segmentation.  Chromic  acid,  the  reagent  most 
frequently  employed  to  harden  these  ova,  readily  alters  the  young 
cells,  and  deforms  the  embryos  by  compressing  them  between  the 
unextensible  envelope  of  the  ovum  and  the  solidified  vitelline  mass. 
For  the  last  two  years  M.  F.  Henneguy  *  has  employed,  in  the  labo- 
ratory of  comparative  embryogeny  of  the  College  of  France,  a  process 
which  allows  the  germs  and  embryos  to  be  extracted  from  the  ova 
of  Trout  and  Salmon  with  the  greatest  facility,  and  without  subjecting 
them  to  the  least  alteration. 

He  places  the  ovum  for  some  minutes  in  a  1  per  cent,  solution  of 
osmic  acid  until  it  has  acquired  a  light  brown  colour ;  then  in  a  small 
vessel  containing  Miiller's  liquid,  and  opens  it  in  this  liquid  with  a 
pair  of  fine  scissors.  The  central  vitelline  mass,  which  is  coagulated 
immediately  on  contact  with  water,  dissolves,  on  the  contrary,  in  the 
Miiller's  liquid,  while  the  solidified  germ  and  cutical  layer  may  be 
extracted  from  the  ovum,  and  examined  upon  a  glass  plate. 

By  treating  the  germ  with  a  solution  of  methyl-green,  and  then 
with  glycerine,  Mr.  Henneguy  was  able  to  observe  in  the  cells  of 
segmentation  the  very  delicate  phenomena  lately  pointed  out  by  Auer- 
bach,  Blitschli,  Strasburger,  Hertwig,  &c.,  and  which  accompany  the 
division  of  the  nucleus,  namely,  the  radiated  disposition  of  the  proto- 
plasm at  the  two  poles  of  the  cell,  the  nuclear  plate,  the  bundles  of 
filaments  which  start  from  it,  and  the  other  succeeding  phases. 

This  fact  proves  that  the  treatment  undergone  by  the  ovum  does 
not  in  any  way  alter  the  elements  of  the  germ. 

To  make  cross  sections  of  the  germs  and  embryos  thus  extracted 
from  the  ovum,  they  should  be  left  for  some  days  in  Miiller's  liquid, 
and  coloured  with  picro-carminate  of  ammonia.  After  having  dehy- 
drated them  by  treating  them  with  alcohol  of  spec.  grav.  0*828,  and 
then  with  absolute  alcohol,  they  are  put  for  twenty -four  hours  into 
collodion.  The  embryo  is  then  placed  on  a  small  plate  of  elder-pith 
*  '  Kevue  Interuat.  cles  Sci.,'  iii.  (1879)  150. 


326  NOTES   AND    MEMORANDA. 

soaked  with  alcohol,  and  covered  with  a  layer  of  collodion.  When 
tho  collodion  has  acquired  a  sufficient  consistency,  very  thin  sections 
may  be  made,  comprising  both  the  embryo  and  the  plate  of  pith ;  and 
these  are  to  be  preserved  in  glycerine.  If  the  sections  cannot  bo  cut 
directly,  the  piece  is  placed  in  the  40  per  cent,  alcohol ;  the  collodion 
then  preserves  its  consistency,  and  allows  the  embryo  to  be  cut  at  any 
time. 

This  process  is  applicable  to  every  kind  of  embryo  of  little  thick- 
ness, allowing  it  to  be  coloured  en  masse.  It  has  the  immense  advantage 
of  enabling  one  to  see  at  what  level  of  the  embryo  each  section  is 
made,  to  preserve  it  in  the  middle  of  a  transparent  mass,  which  main- 
tains all  the  parts,  and  prevents  their  being  damaged,  as  very  often 
happens  when  an  inclusory  mass  is  employed,  from  which  the  section 
must  be  freed  before  mounting  it. 

In  his  '  Precis  de  Technique  Microscopique '  M.  Mathias  Duval 
has  already  recommended  collodion  for  embryological  researches,  but 
without  indicating  his  mode  of  employing  it.  We  hope  to  render  a 
service  to  embryologists  by  making  known  a  process  which  may  be  of 
some  utility. 

Improvement  in  Aerating  Apparatus  of  Sea-water  Aquaria.— 

Dr.  H.  Lenz,  of  Liibeck,  has  employed  with  success  the  following 
method  (suggested  to  him  by  Mr.  A.  Sasse,  of  Berlin)  for  producing 
very  minute  air-bubbles  from  the  aerating  apparatus.  The  aperture 
of  the  glass  tube,  instead  of  being  drawn  out  into  a  fine  point,  is 
widened  to  6-8  mm.,  or  a  glass  tube  25  mm.  long  and  6-8  mm.  wide 
is  cemented  with  sealing-wax  on  to  the  short  discharging  arm.  A  piece 
of  common  sponge  is  then  pressed  pretty  tightly  into  the  wide  opening. 
Instead  of  the  somewhat  large  single  air-bubbles,  we  then  have 
hundreds  of  very  small  ones  in  clusters,  and  the  tighter  the  sponge  is 
pressed  in,  the  smaller  they  become. 

By  this  means  the  air  is  as  finely  divided  as  by  the  syringe  appa- 
ratus of  the  large  aquaria.  Very  slight,  if  any,  increase  of  pressure 
is  found  necessary ;  and  should  in  time  algfe,  &c.,  become  attached  to 
the  sjionge,  it  can  easily  be  taken  out  and  cleansed.  Dr.  Lenz  used 
his  sponge  for  three  months  before  it  wanted  cleaning.* 

Further  Improvements  in  studying  the  Optical  Characters  of 
Minerals. — Mr.  H.  C.  Sorby  has  lately  improved  his  method  of 
studying  the  optical  characters  of  minerals.     He  says :  f — 

"  It  is  a  curious  example  of  how  a  method  may  be  invented  and 
then  lost  sight  of,  that  the  determination  of  the  index  of  refraction 
in  tho  way  I  have  previously  described,  was  proposed  by  a  French 
savant  upwards  of  a  hundred  years  ago.  I  have  not  yet  consulted  the 
original  publication,  but  I  very  strongly  suspect  that  the  proposal  was 
more  theoretical  than  practical,  and  that  with  the  instruments  then  at 
disposal  the  results  were  found  to  be  so  iuexact  that  the  whole  system 
became  obsolete  and  practically  forgotten.  I  may,  however,  claim  to 
have  so  modified  the  method,  and  brought  the  instrumental  means  to 

*  'Zool.  AnzuigLT.'  ii.  (1879)  20. 

t  '  Mincralogical  Magazine,'  ii.  (1878)  103. 


NOTES   AND    MEMORANDA.  327 

such  perfection,  as  to  make  it  fully  equal  to  the  requirements  of  pi'ac- 
tical  mineralogy.  Whilst  si^eakiug  on  this  point,  it  may  be  well  to 
give  an  illustration  of  the  accuracy  with  which  it  is  possible  to 
measure  the  index  with  the  ajjparatus  which  I  have  now  at  disposal. 
Thus,  in  the  case  of  a  sj)ecimen  of  quartz,  about  "372  inch  thick,  five 
diti'ereut  determinations  of  the  index  of  the  ordinary  ray  for  the  light 
transmitted  by  red  glass,  which  corresponds  to  the  solar  line  c,  were 
1-5513,  1-5531,  1-5524,  1-5531  and  1-5513,  so  that  no  observation 
differed  more  than  a  unit  in  the  third  place  of  decimals  from  the 
mean  value,  which  may  therefore  be  looked  upon  as  true  to  the  third 

T 

place  of  decimals,  assuming  that  the  equation  /a  = needs  no 

correction. 

There  was  no  difficulty  in  thus  proving  that  there  is  a  slight  but 
well-marked  difference  in  the  index  for  different  specimens.  The 
mean  for  five  was  1  -  5543,  whereas,  according  to  Rudberg,  it  is  1  -  5418. 
In  a  similar  manner  I  found  that  my  method  invariably  gave  too  high 
a  result  in  the  case  of  other  minerals.  After  many  careful  measure- 
ments I  came  to  the  conclusion  that  this  can  be  satisfactorily  attri- 
buted to  the  spherical  aberration  due  to  the  introduction  of  a  trans- 
parent plate  in  front  of  the  object-glass,  as  suggested  by  Professor 
Stokes.  The  amount  of  this  error  depends  partly  on  the  index  of 
refraction,  and  partly  on  the  special  correction  of  each  particular 
object-glass ;  and  when  great  accuracy  is  desired,  it  is  necessary  to 
construct  a  small  table  showing  the  amount  that  must  be  deducted  in 
each  case.  I  thus  find  that,  when  using  my  f  object-glass,  if  the 
index  is  about  1-5  1  must  deduct  -0100,  and  when  2-0,  must  deduct 
•0180. 

Having  thus  shown  how  accurately  the  index  may  be  measured,  it 
may  be  well  to  briefly  allude  to  some  improvements  in  the  apparatus. 
I  find  two  cross  lines  in  the  fucus  of  the  eye  lens  very  useful  in 
keejiing  constant  the  focal  adjustment  of  the  eye  itself.  In  adjusting 
the  focus  of  any  object  it  is  always  arranged  so  that  the  cross  lines  are 
also  in  sharp  focus.  Without  this  precaution  there  may  be  an  im- 
portant difference,  according  as  the  focus  is  adjusted  by  moving  the 
object-glass  up  or  down.  I  have  also  found  it  desirable  to  take  the 
means  of  two  or  more  sets  of  measurements  made  in  slightly  different 
parts  of  the  scale,  so  as  to  eliminate  any  error  due  to  imperfect  gradua- 
tion. This  is  easily  managed  by  moving  the  fine  adjustment.  It  is 
by  adopting  these  precautions  that  I  have  been  able  to  make  such 
concordant  and  accurate  measurements  as  those  given  above  in  the  case 
of  quartz,  and  to  prove  that  the  limit  of  error  may  be  made  very  small. 

When  first  I  commenced  to  apply  my  method  to  the  study  of 
various  minerals,  with  the  view  of  comparing  mathematical  theory 
with  observation,  I  soon  found  that  there  were  a  few  discrepancies. 
For  some  time  I  thought  it  just  possible  that  these  might  be  due  to 
errors  in  the  measurements,  but  I  found  that  these  discrepancies 
became  the  more  and  more  marked  as  by  degrees  I  was  able  to  remove 
every  api)arent  source  of  error.  The  principal  discrepancy  is  in  the 
case  of  bi-axial  crystals  like  aragonite,  but  some  are  also  met  with  in 


328  NOTES   AND   MEMORANDA. 

the  case  of  uniaxial  crystals.  I  have  not  yet  been  able  to  thoroughly 
ascertain  the  laws  which  govern  these  special  peculiarities,  and  no 
kind  of  explanation  has  yet  suggested  itself  either  to  Professor  Stokes 
or  myself ;  and  therefore  it  appears  to  me  undesirable  to  enter  more 
fully  into  the  question,  which  relates  more  to  the  mathematical  theory 
of  light  than  to  practical  mineralogy.  It  may,  however,  be  well  to 
say  that  the  discrepancy  to  which  I  refer  is  in  the  ratios  of  the  values 
of  the  real  and  apparent  indices." 

Mr.  Sorby  gives  an  illustration  of  the  application  of  the  method  to 
the  identification  of  doubtful  minerals,  in  the  case  of  certain  crystals, 
which  he  determined  to  be  an  unusual  secondary  form  of  calcite. 

Improved  Achromatic  Condenser. — Messrs.  E.  and  J.  Beck  have 
introduced  a  modification  of  the  achromatic  condenser,  in  which  a 
series  of  combinations  of  lenses  are  made  to  revolve  excentrically,  so 
as  to  be  brought  consecutively  into  combination  with  a  lower  fixed 
series  of  lenses.  The  apertures  vary  from  40°  to  170'',  and  two  of  the 
revolving  combinations  are  truncated  and  blackened,  so  as  to  stop  out 
the  central  rays  to  the  limits  of  GO'^  and  120°. 

The  latest  addition  to  the  instrument  consists  of  the  application 
of  a  revolving  diaphragm,  with  various  sized  apertures  beneath  the 
entire  combinations. 

Seller's  Mechanical  Microtome. — Dr.  Carl  Seiler,  of  Philadelphia, 
is  the  inventor  of  an  apparatus  for  enabling  the  knife,  in  cutting 
sections,  to  be  carried  through  the  tissues  with  an  even  motion  and 
at  the  same  inclination — a  necessary  point  to  ensure  success,  but  not 
so  easy  as  might  be  imagined,  because  the  hands  usually  are  not  sufii- 
ciently  steady  without  a  great  deal  of  practice. 

It  occurred  to  Dr.  Seiler,  therefore,  that  if  the  knife  could  be 
rigidly  fastened  to  some  apparatus  by  means  of  which  it  could  be 
moved  over  the  well  of  the  microtome  in  the  same  manner  that  the 
hands  move  it,  sections  of  any  size  and  thinness  could  easily  be  made, 
even  by  an  unpractised  hand  ;  and  after  some  experimenting  he  con- 
structed, with  the  aid  of  Mr.  Zentmayer,  a  mechanical  microtome 
which  proved  to  be  all  that  could  be  desired. 

It  consists  of  two  rigid,  parallel  arms  of  metal,  which  at  one  end 
revolve  on  pivots  attached  either  to  the  microtome  itself,  or  to  the 
table  to  which  the  microtome  is  to  be  clamped.  On  the  other  end  of 
these  arms  are  fastened  revolving  clamps  which  hold  the  knife,  the 
edge  of  which,  when  in  position,  rests  upon  the  glass  plate  of  the 
microtome.  The  handle  of  the  knife  is  removed,  so  as  to  prevent  a 
slipping  and  hindrance  to  the  motion  of  the  knife,  but  can  be  easily 
attached  by  means  of  a  screw,  for  the  purpose  of  stropping. 

When  in  position  and  ready  for  cutting,  the  knife  is  pressed  upon 
the  glass  plate,  and  a  slight  side-motion  is  given  to  it  by  the  hands, 
which  causes  it  to  pass  through  the  tissue,  and  cut  a  thin,  even  section 
without  difficulty.  With  this  apparatus  he  was  able  to  cut  a  thin 
section  of  the  leg  of  a  five  months'  fcetus,  from  the  knee  downward, 
including  the  foot,  the  section  measuring  2  inches  in  length  by  f  inch 
in  width.     Several  mechanical  microtomes  have  been  constructed  by 


NOTES    AND    MEMORANDA.  329 

various  workers,  but  to  his  knowledge  they  are  all  deficient  in  one 
l^oint,  viz.  the  knife  or  cutting  instrument  in  them  is  carried  through 
the  tissue  like  a  chisel ;  or,  in  other  words,  the  cutting  edge  is  pressed 
through  the  tissue.     But  a  knife,  in  order  to  cut  well  and  evenly, 


must  be  carried  through  the  substance  to  be  cut,  especially  if  it  is 
soft,  in  a  slanting  direction,  so  that  each  point  of  the  edge  describes  a 
curve  which  is  equal  to  a  part  of  a  circle.  By  referring  to  the  figure 
it  will  be  seen  that  in  Dr.  Seiler's  apparatus  this  is  exactly  what 
takes  place  when  the  knife  is  moved,  the  radius  of  the  curve  being  tlic 
length  of  the  arms  from  the  centre  of  the  clamps  to  the  centre  of  the 
pivots.* 

Size  of  Histological  Preparations. — Dr.  Seiler,  in  the  same  article 
("  Practical  Hints  on  Preparing  and  Mounting  Animal  Tissues "), 
considers  that  the  advantage  of  having  the  sections  of  sufficient  size  to 
bring  into  view  the  different  parts  of  which  it  is  composed  has  not  as 
yet  received  sufficient  attention  from  microscopists,  especially  from 
those  engaged  in  the  study  of  pathological  histology,  and  yet  it  is  of 
the  greatest  importance,  for  very  frequently  a  pathological  new  growth 
will  present  different  appearances  in  different  parts,  and  often  an 
erroneous  conclusion  is  arrived  at  in  regard  to  the  nature  of  the  tissue 
from  the  fact  that  but  a  small  section  has  been  examined. 

"Microscopy"  and  "Microscopical"  Societies. — Under  the 
title  of  "  Is  there  a  Science  of  Microscopy  ?  "  we  gave  at  jjage  3G5 
of  vol.  i.  an  extract  from  an  article  by  the  Editor  of  the  '  American 
Quarterly  Microscopical  Journal,'  and  stated  our  intention  of  adding 
in  a  later  number  a  translation  of  an  article  by  Dr.  Kaiser,  the 
Editor  of  the  Berlin  '  Zeitschrift  fiir  Mikroskopic.'  This  intention 
we  are  obliged  to  abandon,  as  we  find  it  impossible  to  do  justice  to 
the  author's  views  within  reasonable  limits  of  space,  the  article 
occupying  twenty-five  pages  of  the  German  Journal.  It  must  snfiice 
here  to  say  that  Dr.  Kaiser,  after  referring  to  Professor  Harting's 
protest  against  the  use  of  the  word  Microscopy,  and  his  attempt  to 
contrast  it  with  Ophthalmoscopy  ("  the  science  of  observation  with 
*  'Amur.  Quart.  Micr.  Journ.,'  i.  (1879)  134. 


330  NOTES   AND   MEMORANDA. 

the  naked  eye  "),  defines  the  former  as  "  a  free  independent  scientific 
discipline  of  the  natural  sciences,"  and  "  claims  the  elementary  forms 
as  the  original  and  jieculiar  domain  of  special  Microscopy." 

It  seems  to  us,  with  all  deference  to  those  who  have  from  time  to 
time  laboured  to  define  "  Microscojiy "  as  some  special  branch  of 
Biology,  that  they  have  been  led  to  a  fallacious  resiilt,  through  a  pre- 
conceived idea  as  to  what  it  would  be  convenient  for  the  definition  to  be. 

There  is,  we  think,  no  need  to  object  to  "  Microscopy "  being 
limited  to  the  Microscope  as  an  instrument  (the  methods  of  its  appli- 
cation as  well  as  its  principles),  and  the  hesitation  to  admit  this  has 
apparently  arisen  on  account  of  objections  that  it  was  thought  would 
then  be  urged  against  the  existence  of  a  "Microscopical"  Society,  to 
which  objections,  however,  there  are  obvious  answers. 

The  first  is,  that  a  "  Microscopical "  Society,  if  "  Microscopy " 
refers  only  to  the  instrument,  is  equivalent  to  a  "  Lancet "  or  a 
"  Theodolite  "  Society. 

Even  if  a  Society  were  established  for  the  single  purpose  of 
dealing  with  the  Microscope  as  an  instrument,  it  would  not  by  any 
means  stand  on  the  same  footing  as  the  Lancet  or  the  Theodolite. 
The  Microscope  is  an  instrument  sui  generis,  and  is  not  comijarable 
with  any  other.  It  is  not  only  as  regards  its  optical  principles  and 
mechanical  form,  but  in  the  various  methods  of  its  application,  that 
it  might  usefully  furnish  scope  for  a  Society  devoted  only  to  those 
points  without  regard  to  any  others.* 

But  further,  it  is  an  entire  misapprehension  if  it  is  supposed  that 
the  objects  of  any  known  Microscopical  Society  of  the  present  day 
are  confined  to  the  Microscope  as  an  instrument.  The  objects  of  this 
Society  in  particular  have  always  been  twofold,  and  have  included  to 
an  equal  extent,  to  say  the  least,  those  branches  of  natural  science 
conveniently  summarized  as  "  the  subjects  of  Microscopical  research," 

The  term  "Microscopical,"  whicb,  as  aj^plied  to  a  Society,  was 
no  doubt  originally  used  in  a  sense  more  nearly  agreeing  with  its 
strict  etymological  meaning,  has  come  to  be  no  more  than  a  sign  and 
a  symbol,  as  much  as  tlie  title  of  '  Lancet '  apj^lied  to  a  newspaper,  or 
those  of  "  Eoyal  "  or  "  Linnean"  to  a  Society. 

When  this  first  objection  is  thus  answered,  it  is  then  said  that 
another  Society  for  the  investigation  of  subjects  of  natural  history  is 
not  required. 

It  must,  however,  be  obvious  that  if  fifty  or  twenty -five  years  ago 
the  Eoyal  Society  and  the  Linnean  Society  were  sufficient  to  meet  the 
requirements  of  the  biology  of  that  day,  the  great  advance  that  has 
been  made  since  that  time,  and  the  enormous  extension  in  the  ground 
to  be  travelled  over,  is  sufficient  to  justify  the  existence  not  of  one 
but  of  several  additional  Societies.     Notwithstanding  that  there  were 

*  The  uiott  recent  instance  of  the  practical  benefit  to  be  derived  from  abstract 
optical  (Microscopical)  principles  is  to  be  found  in  the  oil-immersion  objectives 
(the  origination  of  which  is  due  to  the  Treasurer  of  this  Society,  Mr.  Stephenson), 
and  which  are  the  outcome  of  the  liigLly  technical,  and  to  the  biologist  no  doubt 
extremely  unintereoling  discussions  on  angular  aperture,  but  which  have  put 
into  his  hamls  a  tool  which  is  admitted  to  mark  a  greater  improvement  in 
the  means  of  investigation  than  any  made  since  the  j^erfectiug  of  achromalic 
objectives. 


NOTES   AND    MEMORANDA.  331 

older  Societies  which  covered  the  same  ground,  there  has  been 
found  to  be  room  for  another  mainly  devoting  itself  to  the  larger 
animals — the  Vertebrata,  and  in  the  same  way  there  was  obviously 
room  for  one  mainly  devoting  itself  to  the  smaller  animals — the 
Invertebrata,  and  to  the  development  and  minuter  structure  of  the 
higher  forms. 

We  therefore  should  define  "  Microscopy  "  as  the  science  and  art 
of  the  Microscope  as  an  instrument  both  in  regard  to  its  theoretical 
principles  and  its  practical  working  ;  but  a  "  Microscopical "  Society, 
as  a  Society  established  on  the  one  hand  for  the  improvement  of  the 
Microscope  and  the  methods  of  its  application  ("  Microscopy  "  proper), 
and  also  for  the  communication  of  observations  and  discoveries  in  the 
various  branches  of  Biology  (Invertebrata,  Cryptogamia,  Embryology, 
Histology,  &c.),  which  more  especially  require  the  aid  of  the  Micro- 
scope for  their  investigation. 

Oil-Immersion  Objectives. — We  are  glad  to  find  that  the  English 
opticians  are  at  length  turning  their  attention  to  these  objectives, 
which  ithas  hitherto  been  impossible  to  procure  of  English  manufacture, 
although  we  believe  we  are  correct  in  saying  that  their  construction 
was  primarily  urged  upon  opticians  in  this  country  when  the  idea  first 
suggested  itself  of  the  desirability  of  oil  objectives. 

Messrs.  Powell  and  Lealand  exhibited  at  the  meeting  of  the 
Society  on  the  9  th  April,  an  i  oil-immersion  objective  of  their  manu- 
facture, and  we  believe  that  the  construction  of  higher  powers  is  being 
proceeded  with. 

Method  of  Preserving  Infusoria,  &c. — A  note  by  M.  A.  Certes  in 
'  Comptes  Kendus '  *  describes  a  method  of  obtaining  permanent 
preparations  of  the  Infusoria,  which  he  hopes  may  help  to  create  col- 
lections of  which  all  the  Museums  of  Europe  are  at  present  deficient. 

The  method  which  he  suggests  is  the  employment  of  the  vapour  or 
a  solution  of  osmic  acid  (2  per  cent.),  the  former,  although  well  known 
in  histology,  "  never  yet  having  been  applied  to  the  Infusoria,"  |  and 
he  claims  that  the  organisms  are  instantaneously  fixed,  so  that  the  least 
details,  cilia,  cirrhi,  flagella,  and  buccal  armatui-e  may  bo  observed 
with  the  highest  powers,  the  Euglente  and  Paramecia  preserving  their 
characteristic  colour.  The  nucleus  and  nucleolus  stand  out  clearly, 
and  show,  when  these  occur,  the  curious  phenomena  described  by 
Balbiani.  The  process  may  be  applied  successfully  not  only  to  the  In- 
fusoria, but  also  to  the  Eotatoria,  Anguillulfe,  Bacteria,  and  Vibrions. 

The  important  point  is  to  make  the  osmic  acid  act  proiuj^tly 
and  with  a  certain  force.  Two  means  are  available  for  obtaining 
this  result  with  some  certainty.  The  first,  which  is  suitable  for 
most  cases,  consists  in  exposing  the  Infusoria  to  the  vapours  of  the 
acid  for  a  period  of  from  ten  to  thirty  minutes.  For  very  contractile 
Infusoria  the  process  is  different,  the  immediate  contact  of  the  osmic 
acid  being  obtained  by  putting  a  drop  of  the  solution  on  the  cover- 
glass  before  placing  the  latter  on  the  di'op  of  water.     The  excess 

*  '  Comptes  Rendus,'  ixxxviii.  (1879)  433. 

t  Compare,  however,  Dr.  Pelletan's  process — this  Journal,  i.  (187S)  189.  Also 
Huxley  and  Martin's  '  Biology.' 


332  NOTES   AND    MEMORANDA. 

of  liquid  is  tlicn  removed  by  blotting-paper,  and  thereby  a  slight 
and  advantageous  pressure  produced  on  the  cover-glass. 

After  the  cover-glass  is  in  place,  two  of  the  opposite  sides  should 
bo  fastened  either  with  paraffin  or  Canada  balsam  to  prevent  displace- 
ment in  colouring. 

To  colour  the  organisms  he  uses  eosin  or  Eanvier's  picro-carminate. 
Infusoria  previously  treated  with  the  osmic  acid  may  be  coloured 
direct  with  the  picro-carminate,  but  when  it  is  employed  alone,  it  is 
not  easy  to  control  the  colouring,  so  that  the  preparations  often  turn 
out  opaque.  After  several  attempts,  he  found  that  a  mixture  of  glyce- 
rine and  picro-carminate  will  enable  any  degree  of  colour  to  be  obtained 
(glycerine  1  part,  water  1  part,  picro-carminate  1  part).  Introduced 
suddenly,  the  glycerine  even  when  diluted  frequently  produces  an 
abnormal  retraction  of  the  tissues,  which  does  not  always  disappear. 
Professor  Ranvier  gives  in  his  '  Histology '  a  very  simple  means  of 
avoiding  this  inconvenience,  which  M.  Certes  has  employed  with 
success  for  the  most  delicate  organisms,  such  as  OxijtricTia  and  Stentor  ; 
it  consists  in  placing  the  preparations,  fastened  as  above  described,  in 
a  moist-chamber,  and  putting  a  drop  of  carmiuated  glycerine  on  the 
edge  of  the  preparation.  The  water  evaporates  very  slowly,  and 
in  twenty-four  hours  is  replaced  by  the  diluted  glycerine.  By  the 
same  process  the  latter  may  be  replaced  by  concentrated  glycerine, 
which  assures  the  preservation  of  the  preparations. 

All  methods  of  sealing  down  may  be  applied.  It  is,  however, 
better  to  use  dry  Canada  balsam  dissolved  in  chloroform.  The 
organism  to  be  examined  might  be  at  the  side  of  the  glass,  and  this 
varnish,  being  thin  and  perfectly  transparent,  does  not  hinder  observa- 
tion even  with  the  highest  powers. 

Mixture  of  Oils  for  Homogeneous-Immersion  Objectives. — Pro- 
fessor Abbe  points  out  that  in  regard  to  the  performance  of  oil- 
immersion  lenses  with  central  light  it  is  a  matter  of  importance  to 
regulate  carefully  the  oil-mixture  as  regards  refraction  and  dispersion. 
He  noticed  some  time  ago  that  some  of  the  samples  of  fennel-oil  and 
olive-oil  were  rather  strong  in  both  respects,  so  that  it  is  possible  that 
better  performance  will  be  got  with  central  illumination  when  a 
small  additional  quantity  of  olive-oil  is  added  for  reducing  the 
refraction  to  that  of  the  oil  of  cedar-wood,  and  then  further  adding 
if  or  I  of  cedar-oil  to  the  mixture  to  reduce  the  dispersion  (the  latter 
specially  for  thin  covers). 

New  Fluids  for  Homogeneous  Immersion.  —  The  result  of 
Professor  Abbe's  later  experiments  will  be  found  at  p.  346  of  the 
'  Proceedings.' 

Standard  Micrometers. — A  letter  from  Professor  R.  Hitchcock 
(the  editor  of  the  '  American  Quarterly  Microscopical  Journal ')  on 
this  subject  is  printed  at  p.  349  of  the  '  Proceedings.' 

Unit  of  Micrometry. — The  resolution  come  to  by  the  meeting 
of  the  Society  on  the  9th  April  will  be  found  at  p.  349  of  the 
'  Proceedings,'  


(    333    ) 
OBITUAEY.* 


Seven  Fellows  have  died  during  the  past  year,  viz.  :— Mr.  E.  J. 
Bagshaw  (London),  elected  1846,  died  14th  August,  1878  ;  Mr.  E. 
Branwell,  M.E.C.S.  (Brighton),  elected  1873,  died  23rd  Septemher, 
1878 ;  Dr.  H.  Owens,  M.D.,  M.E.C.S.  (London),  elected  1867,  died 
9th  September,  1878  ;  Captain  E.  W.  Eoberts,  F.E.G.S.  (Boxmoor), 
elected  1866,  died  12th  June,  1878  (of  whom  we  have  not  received 
any  Obituary  Notices)  ;  and  the  following : — 

Mr.  John  Egbert  Burton  (a  successful  merchant,  and  one  of  the 
founders  of  the  "  British  Empire  Life  "  and  "  Perpetual  Building 
Society,"  on  the  management  of  which  he  continued  to  the  last)  died 
at  his  residence,  Huskards,  Ingatestone,  on  the  20th  November,  1878. 
He  was  elected  a  Fellow  of  the  Society  in  1861,  and  though  rarely 
seen  at  the  meetings,  was  much  attached  to  the  use  of  the  Micro- 
scope, and  occupied  himself  in  his  leisure  hours  with  mounting  objects. 

Mr.  George  Guyon  was  a  descendant  (the  great-grandson)  of  the 
famous  French  Huguenot  family  of  Guyon  ;  the  head  of  which,  Guyon 
de  Geis,  Sieur  de  Pampelona,  came  over  to  England  at  the  Eevoca- 
tion  of  the  Edict  of  Nantes,  and  took  service  under  William  III. 
He  was  born  at  Eichmond,  in  SiU'rey,  on  March  10th,  1824,  after 
the  younger  of  the  senior  members  of  his  family  had  grown  up.  One 
of  these,  General  Guyon,  became  famous  subsequently  for  his  defence 
of  Ears  (in  conjunction  with  Sir  Fenwick  Williams)  against  the 
Eussians. 

From  his  birth  Mr.  Guyon  was  so  delicate  as  to  preclude  the  pos- 
sibility of  his  being  educated  for  any  profession.  He  very  early 
exhibited  the  strongest  predilection  for  science,  and  especially  for 
natural  science,  devoting  himself  at  one  period  of  his  life  largely 
to  Entomology.  He  leaves  an  extensive  and  valuable  collection  of 
Coleoptera.  He  later  took  up  the  Microscope  enthusiastically,  and 
became  an  expert  and  dexterous  manipulator.  His  neatness  in 
mounting  objects  was  remarkable,  and  he  had  accumulated  a  large 
number  of  specimens  illustrative  of  various  branches  of  natural  his- 
tory. By  his  physician's  order,  he  was  for  some  years  compelled  to 
pass  the  winter  at  Ventnor,  which  he  ultimately  made  his  permanent 
residence,  and  where  he  erected  an  astronomical  observatory,  furnished 
with  a  fine  equatorial,  &c. 

There  were  few  more  delightful  men  in  society  than  Mr.  Guyon. 
His  varied  and  extensive  reading  supplied  an  inexhaustible  fund  of 
conversation ;  while  his  numerous  accomplishments,  and  unflagging 
readiness  to  enter  into  any  scheme  of  amusemeut  or  instruction,  ren- 
dered him  a  favourite  both  with  old  and  young.  Nor  was  his  pen  idle. 
He  contributed,  propria  nomine,  and  under  his  initials  "  G.  G.,"  pretty 
frequently  to  'Science-Gossip';  appearing  at  other  times  as  "Vec- 
tensis "  in  the  '  English  Mechanic'  Lastly,  he  was  a  munificent 
anonymous  donor  to  nearly  all  the  leading  charities  in  England. 

*  Pressure  on  our  space  made  it  necessary  to  omit  this  in  the  last  number.     It 
should  have  accompanied  the  Report  of  the  Council. 


334  OBITUARY. 

Ho  was  elected  a  Follow  of  this  Society  in  1858,  and  died  25th 
Felirnaiy,  1878,  in  his  fifty-fonrth  year. 

Dr.  Edward  James  Shearman,  M.D.,  F.E.S.E.,  F.L.S.,  &c.,  who 
died  at  Kotherham  on  the  2nd  October,  1878,  in  his  eighty-first  year, 
was  born  at  Wrington,  in  Somersetshire,  next  door  to  the  celebrated 
Hannah  Moore,  and  received  his  early  education  at  Mr.  Catlow's 
School,  at  Mansfield,  where  he  was  articled  to  a  surgeon.  He  passed 
the  Apothecaries'  Company  in  1820,  having  had  the  opportunity  of 
studying  under  Brodie  (afterwards  Sir  B.  C.  Brodie),  at  St.  George's 
Hospital,  and  settled  at  Kotherham  about  1823,  where  he  very  soon 
took  a  leading  position  as  a  general  practitioner  in  the  town  and 
neighbourhood.  He  afterwards  passed  the  College  of  Surgeons,  and 
some  ten  years  ago  was  made  a  Fellow.  He  took  the  degree  of  M.D. 
of  Jena  in  1841,  and  became  a  Member  of  the  Boyal  College  of  Phy- 
sicians, London,  in  1869,  having  obtained  the  extra  Licentiate  in  1843. 

His  contributions  to  medical  literature  have  been  numerous  and 
varied  in  almost  all  the  journals  of  his  time.  In  1845  he  published  an 
"Essay  on  Properties  of  Animal  and  Vegetable  Life."  In  1846  he  was 
elected  one  of  the  Council  of  the  Provincial  Medical  Association,  and 
in  1847  was  appointed  to  write  the  "  Eetrospective  Address  on  Diseases 
of  the  Chest,"  which  was  read  by  his  son  in  1848  at  the  annual  meet- 
ing, and  was  afterwards  published  by  the  Council.  He  was  elected  a 
Fellow  of  the  Ptoyal  Society  of  Edinburgh,  of  the  Medico-Chirurgical 
Society,  and  of  several  other  learned  bodies.  In  1856  he  was  elected 
a  Fellow  of  this  Society,  having  been  early  associated  with  the  pio- 
neers of  the  Microscope  in  medicine,  and  he  continued  to  the  last 
to  manifest  a  most  striking  love  for  microscopical  science,  in  diag- 
nosis of  disease,  of  which  he  had  early  become  an  adept.  More  than 
twelve  months  before  Dr.  Golding  Bird  published  his  first  edition  of 
'  Urinary  Deposits,'  he  read  before  the  ShefiSeld  Medico-Chirurgical 
Society  an  "  Essay  on  the  Changes  in  the  Urine  affected  by  Disease," 
and  the  tests  to  distinguish  them,  which  was  published  in  the  '  Lancet ' ; 
and  the  information  which  he  gave  to  the  town  on  sanitary  matters 
was  very  interesting,  exposing  the  evils  which  existed  at  the  time, 
which  attached  more  particularly  to  bad  water  and  faulty  drainage. 
His  microscopical  examinations  of  the  water  caused  great  alarm,  and 
thoroughly  opened  the  eyes  of  the  people  to  the  unsanitary  condition 
of  the  town  as  regarded  sewage  and  water,  and  paved  the  way  for  a 
new  and  better  era. 

He  was  married  twice,  first  to  the  daughter  of  Mr.  Brooks,  of  Old 
Moor,  Wath,  by  whom  he  had  three  children ;  the  death  of  his 
surviving  son.  Dr.  Charles,  who  died  about  fourteen  years  ago,  aged 
fiity,  was  a  great  blow  to  him,  as  he  was  a  man  of  acumen  and  great 
promise  in  his  profession.  In  1872  he  was  married  to  Miss  Turner, 
of  South  Grove,  who  survives  him.  Dr.  Shearman  was  held  in  the 
highest  esteem  by  large  numbers,  not  only  of  friends,  but  of  patients 
in  various  parts  of  the  country,  who  had  been  in  the  habit  of  con- 
stantly consulting  him. 


(     335     ) 

BIBLIOGEAPHY 

of  Invertebrafa,  Crypiogamia,  Embryology,  Histology, 
Microscojjy,  &g. 


JOURNALS,  TRANSACTIONS,  &c.,  received  since  the  last  number, 

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Universal  Sub-Stage  for  Oblique  Light.  Am.  Journ.  Micr.,  IV.,  No.  2. 

Vanden  Broeck.  E. — Medley  of  Microscopy.     Notices,  &c.,  presented  to  the 
Belirian  Society  of  Microscopy.     (8vo.     Brussels,  1879.) 
WiLKiNS,  T.  S. — Microscopic  Pond  Life  {continued). 

Am.  Joum,  Micr.,  IV.,  No.  2. 


(     344    ) 
PROCEEDINGS  OF  THE  SOCIETY. 


Meetings  of  9th  April,  1879,  at  King's   College,  Strand,  W.C. 
Db.  Beale,  F.E.S.,  President,  in  the  Chair. 

The  Minutes  of  the  meeting  of  12th  March  last  were  read  and 
confirmed,  and  were  signed  by  the  President. 


The  List  of  Donations  (exclusive  of  exchanges)  received  since  the 

last  meeting  was  submitted,  and  the  thanks  of  the  Society  given  to 

the  donors. 

From 

Ardissone,  F. — ^Le  Floridee  Italiche  descritte  ed  illustrate. 

Vol.  i.  fasc.  v.,  2  plates,    8vo.    Milan,  1874        The  Author. 

La  Vie  des   Cellules  et   I'lndividualite'  dans  le   Eepjne 

Ve'ge'tal.     Traduit  par  A.  Champseix.     8vo.     Milan,  1874        Ditto. 

Carus,  J.  Victor,  and  W.  Engelmann. — Bibliotheca  Zoologica. 

2  vols.    8vo.     Leipzig,  1861 Dr.  Beale. 

Gegenbaur,    C. — Grundziige    der   Vergleichenden    Anatomie. 

(319  woodcuts.)     2teAufl.     8vo.     Leipzig,  1870       ..      ..         Ditto. 

Home,  Sir  Everard,  Bart. — Lectures  on  Comparative  Anatomy. 

(171  plates.)     Vols.  iii.  and  iv.     4to.     London,  1823        ..      Mr.  Crisp, 

Orth,  Dr.  J. — A  Compend  of  Diagnosis  in  Pathological  Ana- 
tomy. Translated  by  Dr.  F.  C.  Shattuck  and  Dr.  G.  K. 
Sabine.  Eevised  by  Dr.  R.  H.  Fitz.  (2  plates).  Svo. 
Boston,  1879      Ditto. 

Pelletan,  Dr.  J. — Le  Microscope:  son  Emploi  et  ses  Applica- 
tions.    (4  plates  and  278  woodcuts.)     Svo.     Paris,  1876   ..     Dr.  Beale. 

Roper,  F.  C.  S.— Flora  of  Eastbourne.     Svo.     London,  1875  ..      The  Author. 

Siebold,  C.  Th.  v.,  and  H.  Stannius. — Comparative  Anatomy. 
Translated  from  the  German  and  edited  by  Dr.  W.  J. 
Burnet.  Vol.i.  Anatomy  of  the  Invertebrata.  Svo.  London 
andTJoston,  1854      Dr.  Beale. 


The  Books  which  the  Council  had  decided  to  purchase  out  of  the 
Quekett  Fund,  in  pursuance  of  their  last  Report,  were  stated  to  be  tho 
following : — 

Encyclopedia  Britannica.     9th  ed.    Vols  i.-ix.    4to.    Edinburgh,  1875-9. 

Botanischer  Jahresbericht.     Vols,  i.-iv.     Svo.     Berlin,  1874-8. 

Zoological  Record.     Vols,  i.-xiii.     Svo.     London,  1875-78. 

Ehrenberg,  C.  G. — Mikrogeologie,  and  Continuation.     Fol.     Leipzig,  1854-6. 

Gegenbaur,  0. — Elements  of  Comparative  Anatomy.     (Translated  by  Bell  and 

Lankester.)     Svo.     London,  1878. 
Haeckel,  E.— Die  Radiolarien.     Fol.     Berlin,  1862. 
Hertwig,  R. — Der  Organismus  der  Radiolarien.     4to.     Jena,  1879. 
Huxley,  T.  H. — Manual  of  the  Anatomy  of  Vertebnited  Animals.    Svo.    London, 

1871. 

Manual  of  the  Anatomy  of  Invertebrated  Animals.     Svo.     London,  1877. 

Nicholson,  H.  A. — Manual  of  Zoology.     5th  ed.     Svo.     Edinburgh  and  London, 

1878. 

Manual  of  Palaeontology.     Svo.     Edinburgh  and  London,  1872. 

Ranvier,  L. — Traite'  teclmique  d'Histologie.     Fasc.  1-5.     Svo.     Paris,  1S75-S. 
Stein,  F.  Ritter  von. — Der  Organismus  der   lufusionsthiere.     Parts  I.  II   and 

III.  (1st  Half).     Fol.     Leipzig,  1859-78. 
Thuret,  G.,  and  E.  Bornct. — Etudes  Phycologiques.     Fol.     Paris,  1878. 

The  books  were  laid  upon  the  table. 


PROCEEDINGS    OF   THE   SOCIETY.  345 

Mr.  Stewart  called  attention  to  two  slides  exhibited  by  Mr. 
Dreyfus,  one  of  which  {Poteriodendron  peiiolatiim)  was  one  of  the 
remarkable  flagellate  Infusoria  (figured  in  Stein's  work),  in  the  form 
of  a  tree  goblets  of  glass-like  transparency,  an  outline  of  which  he 
drew  on  the  board.  It  had  been  found  in  one  of  the  ponds  at  the 
Zoological  Gardens.  The  other  slide  was  a  fungus  {Gymnospor- 
angium),  one  of  the  Uredinece. 


Mr.  Crisp  called  attention  to  the  fact  of  Messrs.  Powell  and  Lea- 
land  having  constructed  a  ^  oil-immersion  objective,  which  they  had 
brought  for  exhibition. 


Professor  Keith's  "  Note  on  Diagrams  exhibiting  the  path  of  a  ray 
through  Tolles'  ^  Immersion  Objective  "  was  read  by  Mr.  Crisp  (see 
p.  269  and  Plate  XII.)  and  the  diagrams  exhibited.  The  original 
diagram  copied  on  p.  143  of  vol.  i.  and  computation  forming 
Plate  YII.  of  that  volume  were  also  shown. 


Mr.  Wenliam's  "  Reply  to  Professor  Keith's  Note  "  (see  p.  270) 
was  read  (see  p.  271). 

Mr.  Crisp  stated  that  the  Council  had  come  to  the  conclusion  that 
it  was  desirable  to  close  the  controversy  on  the  aperture  question,  and 
that,  with  the  possible  exception  of  a  paper  promised  by  Professor 
Abbe,  it  was  not  intended  to  print  any  further  communications  on  the 
subject  beyond  those  read  this  evening. 


Mr.  Tolles'  paper  on  "  An  Illuminating  Traverse-Lens  "  was  read 
by  Mr.  Crisp,  and  the  apparatus  exhibited  and  illustrated  on  the  black- 
board. 

Dr.  Edmunds  said  that  homogeneous  immersion  was  nothing  less 
than  a  new  point  of  departure  for  high-power  objectives — such  lense-; 
going  as  far  beyond  water  lenses  as  these  go  beyond  air  lenses.  The 
enormous  resolving  power  of  homogeneous  immersion  lenses  could 
only  be  brought  out  by  corresponding  illumination.  For  such  illu- 
mination the  immersion  principle  was  indispensable.  He  had  long 
worked  with  immersion  illuminators,  and  found  them  perfectly  easy 
to  manage.  A  crown  lens,  half  an  inch  in  radius  and  in  depth  an 
entire  hemisphere  minus  the  thickness  of  the  slide,  would,  when  con- 
nected to  the  slide  with  oil,  do  almost  everything  in  the  way  of 
oblique  illumination,  and  no  Microscope  was  now  complete  without 
such  an  accessory.  The  travelling  plano-concave  addendum  of 
Mr.  Tolles,  though  very  pretty  in  theory,  was  not,  he  thought,  of  much 
use  as  a  working  tool. 


Dr.  Hudson's  "  Note  on  Mr.  Deby's  paper  "  (as  to  the  identity  of 
Pedalion  Hudson  and  Hexartlira  Schmarda— see  p.  Ill)  was  read  by 
Mr.  Crisp,  and  the  two  comparative  drawings  made  by  Dr.  Hudson 
enlarged  on  the  board  by  Mr.  Stewart. 


346  PROCEEDINGS   OF   THE    SOCIETY. 

Mr.  Crisp  said  that  at  the  last  meeting  mention  was  made  (see 
p.  220)  of  some  experiments  which  Professor  Abbe  was  conducting 
with  the  view  of  finding  some  immersion  fluid  that  coukl  be  substituted 
for  oil,  and  chloride  of  zinc  was  referred  to  as  a  possible  fluid.  After 
the  meeting,  however,  some  of  the  Fellows  expressed  the  opinion  that 
chloride  of  zinc  would  diss(dve  the  brass  setting  of  the  objectives, 
in  consequence  of  which  Mr.  Stephenson  had  communicated  with 
Professor  Abbe  on  the  subject,  and  in  reply  he  said  that  "  what  he 
spoke  of  was  not  the  ordinary  chloride  of  zinc,  obtained  by  dissolving 
zinc  in  hydrochloric  acid,  but  the  chloride  released  from  water 
(anhydric)  by  distilling  it  over.  The  ordinary  zinc  salt  would  not 
give  sufficient  refraction." 

Mr.  Zeiss  had  also  sent  over  four  samples  of  the  following  solutions 
(which  were  shown  to  the  Meeting),  viz. : — 

(1)  Chloride  of  cadmium  in  glycerine  (CdClo),  1"504. 

(2)  Copaiva  balsam  oil,  1  "504. 

(3)  Chloride  of  zinc  in  water  (ZuCl^),  1-504. 

(4)  Sulpho-carbolate  of  ziuc  in  glycerine,  1  "501. 

The  chloride  of  cadmium  in  glycerine  Professor  Abbe  describes 
as  somewhat  too  thick  for  convenient  use,  but  very  good  in  optical 
respects.  It  is  literally  "  fluid  crown  glass,  its  dispersion  being  almost 
equal  to  that  of  ordinary  crown.  The  oil  of  copaiva  balsam  he 
pronounces  to  be  "  in  every  respect  perfectly  equal  to  oil  of  cedar-wood, 
but  not  quite  so  fluid." 

Mr.  Stephenson  said  that  just  before  he  came  to  the  meeting  he 
had  received  a  letter  from  Professor  Abbe  (7th  April),  in  which  he 
further  said,  "  As  to  the  chloride  of  zinc,  we  have  tried  it  repeatedly, 
and  have  found  no  obstacle,  but  it  does  not  allow  a  prolonged  immer- 
sion with  the  same  drop.  After  ten  to  fifteen  minutes'  exposure,  it 
deposits  small  crystals,  as  it  seems,  on  the  slide  and  on  the  front  lens, 
whereby  the  optical  efiect  is  considerably  deteriorated,  though  all  can 
be  cleaned  off  by  water  and  alcohol.  In  using  this  solution,  therefore, 
the  slide  and  objective  should  be  cleaned  after  ten  minutes'  observation, 
and  a  fresh  drop  taken.  If  the  objective  is  well  cleaned  at  the  end  of 
the  observation,  wiping  it  finally  with  alcohol,  there  will  be  no  damage 
at  all.  With  the  glycerine,  good  cleaning  of  the  preparations  and  of 
the  objective  is  also  necessary,  as  glycerine  has  a  very  strong  adhesion 
to  glass." 

Mr.  Ingpen  inquired  if  there  would  be  any  difiiculty  in  making 
the  ends  of  the  fronts  of  the  objectives  of  platinum  ? 

Dr.  Edmunds  said  that  he  had  written  to  Herr  Zeiss  suggesting 
that  the  front  lens  should  be  set  in  platinum,  because  of  its  incorrodi- 
bility,  and  because,  imder  variations  of  temperature,  its  coefficient  of 
expansion  was  almost  identical  with  that  of  crown  glass.  Herr  Zeiss, 
while  admitting  these  advantages  in  platinum,  pointed  out  that  its 
want  of  rigidity  was  fatal,  inasmuch  as  for  the  fronts  of  these  high- 
angled  lenses,  the  setting  had  to  be  turned  out  very  hollow,  and  to  an 
edge  little  thicker  than  a  sheet  of  writing  paper.  Such  a  setting 
if  in  platinum  would   collapse  under  slight  pressure,  and  the  lens 


PROCEEDINGS   OF    THE   SOCIETY. 


347 


would  b3  spoilt.      Therefore   Herr  Zeiss   used  a   very  Lard  nickel 
alloy. 

As  to  aqueous  fluids,  great  caution  was  needed,  as  some  of  them  might 
corrode  the  metal  setting,  and  unship  the  front  leus ;  some,  such  as 
zinc  chloride,  would  be  very  hygroscopic,  and,  after  a  few  minutes  in 
a  dry  or  moist  atmosphere,  would  vary  so  rapidly  in  refractive  index 
as  to  be  useless  for  such  a  purpose  ;  others  would  penetrate  by  capillary 
attraction  past  the  edge  of  the  lens,  and  gum  up  the  margin  of  the 
back  surface,  so  as  to  reduce  the  working  angle  of  the  lens  and  intro- 
duce diffraction  phenomena.  Therefore  an  oily  fluid  would  probably 
after  all  prove  the  best.  Shellac  was  proof  against  cedar  oil,  and 
would  answer  perfectly  for  mounting  objects,  and  perhaps  also  for 
consolidating  the  front  lens  in  its  narrow  setting,  so  as  to  prevent 
capillary  action  at  its  margin. 

A  letter  was  read  from  Mr.  Adolf  Schultze,  of  Glasgow,  well 
known  as  an  expert  manipulator,  in  which  he  said  that  "  though  he 
had  not  had  time  to  examine  these  fluids  closely,  yet  he  was  able  to 
say  that  by  their  use  with  the  -^^  he  at  once  resolved  A.  pellucida 
and  other  fine  diatomaceous  tests  as  distinctly  as  with  cedar-wood  oil. 
The  cadmium  chloride  in  glycerine  and  sulpho-carbolate  of  zinc  in 
glycerine  being  very  thick  and  sticky,  might,  he  thought,  suit  the 
I  well,  as  it  has  a  very  large  working  distance.  Copaiva  balsam  oil 
he  thought  on  the  whole  the  best  substitute  for  cedar-wood  oil. 
Although  these  liquids  do  not  act  as  solvents  on  the  Canada  balsam 
and  the  varnish  rings  of  objects,  and  (with  the  exception  of  the 
copaiva)  are  free  from  smell,  yet  he  doubts  whether  their  use  ofiors 
any  important  advantages  over  cedar-wood  and  fennel  oil,  whose 
smell  is  not  oflensive  if  employed  in  very  small  quantities.  Three  of 
the  four  fluids  require  to  be  washed  oft'  from  the  slide  and  the  front 
leus  with  water,  whilst  for  copaiva  and  the  other  oils  a  little  blotting 
paper  suffices." 

With  regard  to  the  ^^  oil-immersion,  Mr.  Schultze  also  said : — ■ 
"  It  is  my  opinion  that  this  lens  is  at  present  perhaps  the  finest 
immersion  objective  of  the  same  focus  made,  and  that  it  is  not  likely 
soon  to  be  surpassed.  My  specimen  (No.  3)  has  a  magnifying  power 
of  980  diameters,  with  Ross's  A  eye-piece,  and  a  working  distance  of 
about  0  •  004  inch,  its  definition  is  very  fine,  and  its  resolving  power 
is  as  remarkably  great  as  that  of  the  }  and  the  j^  of  the  same  series. 
Its  field  is  quite  flat,  as  far  as  I  can  sec  on  the  tests  at  my  command, 
and  it  gives  a  great  deal  of  light,  so  much  so  that  when  using  a 
microscopic  lamp  with  a  wick  half  an  inch  broad,  the  markings  of 
A.  pellucida  are  still  visible  under  Ivoss's  F  eye-piece,  or  under  a 
])ower  of  8000  diameters.  A2)art  from  magnification  and  working 
distance  there  seems  little  to  choose  regarding  other  optical  qualities 
between  Zeiss's  three  objectives  of  i,  yV,  and  -^  inch  focus  on  the 
homogeneous  immersion  system." 


Mr.  Stephenson,  in  reading  his  paper  on  "  The  Vertical  Illumi- 
nator and  Oil-Immersion  Objectives  "  (see  p.  266),  said  that  it  was  now 
found  that  the  kind  of  illumination  furnished  by  the  vertical  illuminator 


348  PROCEEDINGS   OF   THE   SOCIETY. 

was  exceedingly  valuable  in  the  case  of  large-angled  objectives.  He  had 
no  valve  of  Amiiliiijleura  pellucida  which  he  had  not  been  able  to 
resolve  although  he  had  been  often  told  by  ojiticians  that  some  of  his 
slides  were  of  no  value,  being  quite  "washed  out";  as  for  Surirella 
gemma,  the  whole  valve  was  seen  to  be  covered  with  knobs.  Mr. 
Morehouse,  in  the  extract  quoted  in  the  last  number  of  the  Journal 
(p.  194),  pointed  out  that  the  vertical  illuminator  would  only  work  well 
with  large  aperture  lenses,  and  it  would  be  found  that  it  was  only 
with  very  large  angles,  exceeding  180°,  that  it  acted  effectively. 

Mr.  Curties  asked  what  Mr.  Stephenson  considered  the  best  form 
of  illuminator. 

Dr.  Edmunds  said  he  would  be  glad  to  know  whether  Mr. 
Stephenson  had  compared  the  reflecting  prism,  the  disk  of  thin 
glass,  and  the  opaque  steel  mirror  as  practical  tools  ?  Would  it  be 
best  to  work  the  illuminator  from  the  side  of  the  Microscope  tube,  or 
in  the  optic  axis,  and  at  what  point  behind  the  objective  would  the 
reflector  work  best  on  the  object,  and  do  the  least  damage  to  the 
image  received  by  the  eye-piece? 

Mr.  Stephenson  said  that  the  apparatus  he  had  used  was  the  one 
with  a  parallel  plate  of  glass.  In  one  respect  a  small  prism  was  no 
doubt  better,  because  with  the  plate  of  glass  light  was  received  from 
both  surfaces,  which  tended  to  confuse  the  image.  The  prism  was 
certainly  better  than  the  steel  disk,  and  it  was  essential  that  it  should 
be  placed  at  the  side  of  the  tube.  Of  course  just  so  far  as  the  prism 
projected  over  the  edge  of  the  objective,  the  aperture  of  the  glass 
would  be  diminished.  Dr.  Carpenter  gave  the  preference  to  the  thin 
glass  disk  over  the  fixed  parallel  plate,  both  on  accoimt  of  its 
superior  reflecting  power,  and  the  ease  with  which  it  could  be  set  at 
any  inclination. 

Mr.  Crisp  said  that  Mr.  Stephenson's  demonstration  of  the  excess 
of  aperture  over  180°  was  the  most  interesting  that  had  yet  been 
suggested  on  that  subject.  With  regard  to  slides  of  Amphipleura 
being  washed  out,  he  had  been  frequently  assured  when  objectives 
were  being  tried  on  his  own  slides,  that  the  slides  were  "  not  those  of 
the  Amphipleura  which  had  markings,  but  a  variety  which  had  no 
markings."  It  should  be  mentioned  that  Mr.  Adolf  Schulze  had 
early  last  year  discovered  the  power  of  the  vertical  illuminator,  when 
used  with  oil-immersion  objectives,  to  resolve  AmpMpleura.  He 
unfortunately  delayed  the  publication  of  the  method  through  an 
accident. 

The  President  being  obliged  to  leave,  the  chair  was  taken  by  Dr. 
Braithwaite,  V.P. 

Mr.  Crisp  brought  forward  the  resolution  of  which  he  gave  notice 
at  the  last  meeting,  as  to  a  standard  unit  of  micrometry.  He  said 
that  he  had  little  to  add  to  what  he  then  stated.  His  motive  in  bringing 
the  resolution  forward  was,  1st,  that  they  as  the  oldest  Microscopical 
Society  in  existence,  should  express  an  opinion  one  way  or  the  other 
on  a  subject  which  was  considerably  agitating  their  fellow  workers  in 
America,  and  2nd,  his  conviction  that  it  would  be  a  grievous  error  for 


PROCEEDINGS    OF    THE   SOCIETY.  349 

any  body  of  microscopists  to  adopt  tlie  -j-^^  of  a  millimetre  for  the 
standard  as  had  been  recommended. 

Dr.  Edmunds  in  seconding  the  resolution  said  that  the  y^^  of  a 
millimetre  was  clearly  too  large,  while  the  yoVo  being  less  than  one- 
seventh  the  diameter  of  a  human  blood-corpuscle,  showed  that  it  was 
sufficiently  small  for  all  the  work  of  practical  histology. 

Mr.  Stephenson  said  that  he  entirely  agreed  with  the  views  which 
Mr.  Crisp  had  expressed  as  to  the  y^^y  of  a  millimetre,  which  was 
obviously  much  too  high  a  standard,  leading  as  it  constantly  would  to 
the  use  of  fractions  of  the  unit  which  it  ought  to  be  one  of  the  essential 
qualities  of  a  standard  to  avoid.  At  the  same  time  ho  considered  that 
the  time  had  not  arrived  when  they  ought  to  formulate  in  a  resolution 
a  positive  injunction  as  to  the  use  of  any  given  standard.  So  far  as 
that  was  desirable,  it  had  already  been  done  by  the  Leyden  resolution 
of  Professor  Suringar      He  would  therefore  move — 

"  That  in  the  opinion  of  this  Society,  the  yj  q-  of  a  millimetre  is 
too  large  a  unit  for  micrometric  measurements,  and  that  it  is 
not  expedient  at  present  to  prescribe  by  any  formal  resolution 
the  adoption  of  a  fixed  standard  for  micrometry." 

Mr.  Michael  thought  that  if  they  were  to  have  a  standard  at  all 
the  one  proposed  was  perhaps  the  best  to  be  adopted.  But  the  ques- 
tion in  his  mind  was,  whether  it  was  desirable  or  convenient  to 
establish  a  special  standard  for  the  purpose  of  microscopy  alone? 
The  greater  part  of  the  work  requiring  measurements  was  done  by 
those  who  engaged  in  it  as  a  part  of  their  ordinary  work,  and  in  such 
case  it  would  be  difficult  to  say  what  was  microscopic  work  to  which 
this  new  standard  was  to  apply  in  place  of  the  ordinary  methods  of 
measurement.  He  thought  therefore  that  the  adoption  of  a  new 
standard  required  very  grave  consideration. 

Mr.  Curties  was  certainly  not  in  favour  of  attempting  to  come  to 
any  decision  now  as  to  the  adoption  of  a  standard. 

The  Chairman,  having  put  the  amendment  to  the  Meeting,  declared 
it  to  be  carried. 


A  letter  from  Professor  E.  Hitchcock,  of  New  York  (of  12th 
March),  as  to  standard  micrometers,  was  read  by  Mr,  Crisp,  of 
which  the  following  is  an  extract: — "As  to  standard  micrometers,  I 
cannot  understand  why  there  is  so  much  ojiposition  to  adoi)ting  a 
standard  division.  I  believe  that  such  a  divison  will  be  adopted  here, 
and  that  the  metric  system  will  supersede  all  others.  It  requires  only 
a  slight  familiarity  with  micrometers  ruled  on  this  system  to  convince 
anyone  of  their  superiority.  As  to  the  question  of  accuracy,  I  assume, 
and  with  propriety,  that  divisions  of  yJo^  mm.,  or  yo^tr  iiich,  can 
be  ruled  so  that  the  variations  from  a  given  standard  are  measured  by 
milliontJis  of  an  inch,  varying  from  i  0  to  ±25  millionths  at  a 
given  temperature.  I  have  a  "  standard  cm,"  in  which  the  average 
variation  in  the  spacing  is  not  far  from  10  millionths  of  a  mm., 
according  to  the  determinations  of  Professor  Rogers,  the  maker.  (I 
speak  from  memory ;  it  may  be  a  little  more  than  this,  but  some  of  the 


350  PROCEEDINGS    OF    THE    SOCIETY. 

variations  arc  only  3  millioutlis.)  The  only  question  remaining  is, 
is  the  standard  from  which  the  work  is  done  true  ?  Well,  I  believe 
it  will  be  shown  that  it  is ;  but  suppose  not,  is  it  not  infinitely  better 
to  have  a  standard  measure,  even  though  it  be  not  an  absolutely  accu- 
rate subdivision  of  a  metre  or  inch,  so  long  as  it  is  possible  to  make 
all  standards  agree,  than  to  have  so  much  confusion  as  we  find  at 
present  ?  I  hope  your  Society  will  take  this  view  of  it,  and  I  am 
sure  that  any  man  who  has  ever  undertaken  t(')  prepare  a  standai-d 
micrometer  for  his  own  use  from  a  comparison  of  those  in  the  market, 
will  need  no  argument  to  convince  him  of  the  value  of  this  under- 
taking. Why  should  we  go  on,  year  after  year,  publishing  microscopic 
dimensions  from  micrometers  which  we  know  are  not  true  ?  All  such 
work  will  need  revision  in  the  future,  if  it  is  of  any  value  at  least. 

I  did  not  mean  to  say  all  this.  However,  I  do  hope  your  Society 
will  have  something  to  say  about  this  matter,  and  co-operate  heartily 
with  what  may  be  done  here.  The  matter  is  in  good  hands  on  this 
side  of  the  water,  and  what  action  is  taken  will  be  final  I  believe. 
Above  all  things,  let  us  try  to  avoid  the  adoj^tion  of  one  standard  here 
and  another  in  England." 

Mr.  Crouch  said  that,  having  had  the  pleasure  of  seeing  Professor 
Kogers  and  his  machine,  he  thought  it  was  not  at  all  likely  that  any- 
one on  this  side  of  the  Atlantic  would  be  disposed  to  go  to  the  expense 
that  had  been  gone  to  in  the  matter  by  that  gentleman. 


The  Chairman  announced  that  the  second  Scientific  Evening  of 
the  Session  would  be  held  on  the  21st  May,  in  the  Library  of  King's 
College.  

A  SPECIAL  GENEEAL  MEETING  was  then  held  pursuant 
to  notice. 

Dr.  Braithwaite  moved,  and  Mr.  Stewart  seconded,  the  following 
resolution  : — 

That  Bye-law  7  be  amended  by  substituting  "31Z.  10s."  for 
"  21Z." 

He  said  that  it  had  been  pretty  generally  found  by  the  scien- 
tific Societies  that  the  Composition  Fee  was  too  low  ;  the  Linnean 
Society  had  recently  raised  it  from  30/.  to  45Z.,  and  the  Council  now 
recommended  a  proportionate  increase.  It  would,  of  course,  apply  only 
to  Fellows  nominated  after  this  date. 

Dr.  Edmunds  considered  that  it  was  not  desirable  that  the  Compo- 
sition Fee  should  be  increased. 

The  resolution  was  put  to  the  Meeting  and  carried,  with  three 
dissentients. 

Mr.  Crisp  moved,  and  Dr.  Matthews  seconded,  the  following  reso- 
lution : — 

That  Bye-law  15  6  (see  p.  212)  be  amended  by  inserting  the 

following  words  at  the  end  of  the  first  paragraph  thereof — 

"  or  of   the  Presidents  or  Chairmen    of  the  Biological  or 

Microscopical  sections  of  such  Societies." 

It  had  been  found  that  some  of  the  Societies  nominated  under  the 


PROCEEDINGS   OF    THE    SOCIETY.  351 

Bye-law  had  separate  Biological  or  Microscopical  sections,  and  it  was 
considered  to  be  more  appropriate  that  in  such  cases  the  President 
or  Chairmen  of  those  sections  should  be  Ex-officio  Fellows  rather 
than  the  Presidents  of  the  Societies.  In  the  Eoyal  Societies  of  the 
Australian  colonies,  for  instance,  the  Governor  of  the  colony  was 
generally  the  President, 

The  resolution  was  carried  unanimously. 

The  following  objects  and  apparatus  were  exhibited:— 

Mr.  Dreyfus: — (1)  Poteriodendron  petiolatum  (Flagellate  Infu- 
soria).    (2)  Gymnosporangium  (Fungus). 

Messrs.  Powell  and  Lealand  : — i  oil-immersion  objective  of  their 
own  manufacture,  shown  with  P.  angidatum. 

Mr.  Stephenson  : — Vertical  illuminator,  with  Zeiss'  oil-immersion 
-j-^  objective,  shown  with  SurireUa  gemma  and  Ampliiplenra  pellucida. 

Mr.  Ward : — Section  of  stem  of  R  dgsonia  heterocUta  (Hima- 
layahs). 

Mr.  Crisp:  —  (1)  Dr.  H.  Hager's  Compressor-Microscope  for 
Trichinfe,  &c.,  combining  a  Compressorium  and  a  Microscope  (Hager, 
'Das  Miki-oskop,'  6th  ed.,  Berlin,  1879,  p.  41).  (2)  Beck's  achromTitic 
condenser  (see  p.  328).  (3)  Two  slides  of  compound  vibration  curves 
by  Mr.  Washington  Teesdale.  (4)  Professor  Keith's  original  com- 
putation and  diagram,  vol.  i.  plate  vii.  and  p.  143,  and  the  further 
drawing  described  in  his  last  paper,  vol.  ii.  p.  269  and  plate  xii. 

New  Fellows.  —  The  following  were  elected  Felloics,  viz. : — 
Captain  Cyril  Frampton,  P.M.  ;  Dr.  W.  M.  Ord,  M.D.,  F.E.C.P. ;  and 
Messrs.  F.  M.  Campbell,  G.  Chandler,  G.  D.  Plomer,  G.  W.  Euffle 
and  J.  J.  Vezey. 

Honorary  Fellows. — Eev.  M.  J.  Berkeley  (Sibbertoft,  Market  Har- 
borough) ;  G.  E.  Waterhouse  (London) ;  W.  Archer  (Dublin) ; 
L.  Pasteur  and  L.  Eanvier  (Paris) ;  P.  J.  Van  Beneden  (Louvain)  ; 
A.  de  Bary  (Strassburg) ;  F.  Cohn  (Breslau)  ;  A.  v.  KoUiker  (Wiirz- 
burg);  C.  Nageli  (Munich);  S.  Schwendener  (Berlin);  A.  Gruuow 
(Berndorf,  near  Vienna) ;  F.  Eitter  von  Stein  (Prague) ;  M.  J. 
Schleiden  (Dorpat)  ;  J.  Leidy  (Philadelphia). 

Societies  wJiose  Presidents  for  the  time  heing  are  Ex-officio 
Fellows  under  Bye-Law  15&. 
UNITED  KINGDOM.  Bristol  Naturalists'  Society 

London  and  Suburbs.  j   (Canterbury.)    East      Kent     Natural 

Quekett  Microscopical  Club  p  ^f^l^  f^'^'^^^l ,  „     .  , 

----'■  -       —  Cardifl  Naturalists  Society 

Eastbourne  Natural  History  Society 

Leeds     Philosophical     and     Literary 

Society 
Liverpool,  Literary  and  Philosophical 

Society  of 
Liverpool,  Microscopical  Society  of 
Manchester,  Literary  and  Philosophical 

Society  of 
(Norwich.)  Norfolk  and  Norwich  Natu- 


South  London  Microscopical  and  Natu- 
ral History  Club 

Croydon  Microscopical  and  Natural 
History  Club 

Provinces. 

Birmingham     Natural     History     and 

Microscopical  Society 
Brighton  and  Sussex  Natural  History 

Society 
Bristol  Microscopical  Society  |       ralists'  Society 


352 


PROCEEDINGS   OF    THE   SOCIETY. 


(Newcastle-upon-Tyne.)  North  of  Eng- 
land Microscopical  Society 

(  „  )     Natural  His- 

tory Society  of  Northumberland, 
Durham,  and  Newcastle-upon-Tyne 

Plymouth  Institution  and  Devon  and 
Cornwall  Natural  History  Society 

Scotland. 

Glasji;ow,  Natural  History  Society  of 
(Perth.)     Cryptogamic  Society  of  Scot- 
land 
(     „     )   Perthshire  Society  of  Natural 
Science 

Ireland. 

Dublin  Microscopical  Club 
Belfast,   Natural    History   and   Philo- 
sophical Society  of 

COLONIES. 

India. 

(Calcutta.)  Asiatic  Society  of  Bengal 
Australasia. 

New  South  Wales,  Linnean  Society  of 

New  Soutii  Wales,  Royal  Society  of 

Tasmania,  Royal  Society  of 

Victiiria,  Royal  Society  of 

(New  Zealand.)  Wellington  Philo- 
sophical Society 

Canada. 
(Halifax.)    Nova  Suotian  Institute  of 

Natural  Science 
Montreal,  Natural  History  Society  of 
(Toronto.)    Canadian  Institute 


UNITED  STATES. 

(Boston.)    American  Academy  of  Arts 

and  Sciences 
Boston  Society  of  Natural  History  ^ 
(Chicago.)    State  Microscopical  Society 

of  Illinois 
New  York  Academy  of  Sciences 
New  York  Microscopical  Society 
Philadelphia,    Academy    of    Natural 

Sciences  of 
San  Francisco  Microscopical  Society 
Troy  Scientific  Association 

GERMANY. 

Berlin,  Gesellschaft  Naturforschender 

Freunde  zu 
(Dresden.)      Naturwissenschaftliche 

Gestllschaft  " Isis " 
(Frankfurt    a   M.)    Senckeubergische 

Naturforscheiide  Gestllschaft 
Gottingen,  K.  Gesellfchaft   der   Wis- 

senschaften  zu 


Jenaisehe    Gesellschaft   fiir    Mcdeciu 

&  Naturwissenschaft 
(Leipzig.)    K.  Sachsische  Gesellschaft 

der  Wissenschaften 

AUSTRIA-HUNGARY. 

Wien,  K.K.  Zoologisch-botanische  Ge- 
sellschaft in 

HOLLAND. 

Haarlem,  Hollandsche  Maatschappij 
der  Wetcnchappen  te  (Socie'te'  Hol- 
landaise  des  Sciences  a  Harlem) 

SWITZERLAND. 

Ba  el,  Naturforschende  Gesellschaft  in 
Bern,  Naturforschende  Gesellschaft  in 
Geneve,  Socie'te  de  Physique  et  d'His- 

toire  Naturelle  de 
(Lausanne.)     Socie'te'    Vaudoise     des 

Sciences  Naturelles 
Zurich,  Naturforschende  Gesellschaft  in 

FRANCE. 

(Amiens.)    Socie'te'  Linn^enne  du  Nord 

de  la  France 
Lyon,  Societe'  Linne'enne  de 
Montpellier,  Academic  des  Sciences  et 

Lettres  de 
(Paris.)     Socie'te  Botanique  de  France 
(     „     )     Socie'te'     Cryptogamique    de 

France 

BELGIUM. 

(Brussels.)    Socie'te  Beige    de  Micro- 

scopie 
(       „       )  Socie'te'  Royale  de  Botanique 

de  Belgique 

ITALY. 

Milano,  Istituto  Lombardo  di  Scienze 

e  Lettere  di 
(      „      )      Societk     Crittogamologioa 

Italiana 
(Pisa.)      Societa    Toscana  di    Scienze 

Natural! 
Torino,  R.  Accademia  delle  Scienze  di 
(Venezia.)      R.     Istituto     Veneto    di 

Scienze,  Lettere,  ed  Arti 

SPAIN. 

(Madrid.)  Sociedad  Espafiola  de  His- 
toria  Natural 

RUSSIA. 

Moscou,   Socie'te  Imperiale  des  Natu- 

ralistes  de 
(Odessa.)     Socie'te'  des  Natural  istes  de 

la  Nouvelle  Russie 


New  York  Botanical  Garden  Librar 


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